Driver side electric seat is stuck in the far forward position and won't move. How do I move it manually or fix the motor.

check track for debris

need to look under seat either debris stuck in track at latch release or cable that is used to release it broke or is disconnected

Yes, if you purchase a manual set is will bolt in just the same so long as its the same model and year as they do change from year to year.

this is all i could find,try this link out... How to move seats manually on Chevy silverado Google Search

You don't mention what year your Yukon is ? This could very well be a control Module problem .
I'll post how the power memory seat's work or are suppose to work !

Memory Seats Description and Operation

Battery voltage is supplied to the memory seat module through a 25 A circuit breaker. The memory seat module supplies the seat adjuster switch assembly with a battery positive reference voltage. While the seat adjuster switches are in an inactive state the switch contacts are closed to the adjuster switch common circuit. When a seat adjuster switch is pressed to an active state the switch contact is closed to the reference voltage circuit. Battery voltage on a switch signal circuit indicates to the memory seat module the switch status is active. Each seat adjuster motor is controlled by the memory seat module through 2 motor control circuits. While the seat adjuster motors are in an inactive state the motor control circuits are closed to ground circuit contacts within the memory seat module. The memory seat module operates the seat adjuster motors by switching one of a motors control circuits to battery voltage. The seat adjuster motors are bidirectional and the direction of adjuster motor rotation is determined by which of the adjuster motor control circuits is switched to battery voltage while the other remains grounded.


Memory Set/Recall Operation
The seat adjuster motors are equipped with internal position sensors. The adjuster motor position sensors are monitored by the memory seat module and are used to determine the seat position when storing or recalling memory settings. The driver seat adjuster motors use potentiometer type position sensors. The position sensors are supplied with a 5 V reference and ground circuits from the memory seat module. The position sensor signal circuits return to an analog input within the memory seat module. During adjuster motor operation the position sensor provides a voltage change proportional to the change in revolution of the adjuster motor shaft. The memory seat module monitors the voltage from the position sensor signal circuits to determine the adjuster motor positions when storing or recalling memory seat position settings.
The memory recall switch assembly on the driver door provides inputs to the driver door lock/window switch. Battery voltage is supplied to the memory recall switch assembly from the driver door lock/window switch. When a RCL 1, RCL 2, or EXIT switch is pressed, the switch contacts close the appropriate switch signal circuit to the battery voltage supply circuit within the memory recall switch assembly. When the driver door lock/window switch receives active switch signals from the memory recall switch assembly, the appropriate commands are sent to the memory seat module using the GMLAN Serial Data circuit. The Body Control Module software version determines the personalization features available.
Memory seat recall operation is allowed only with the transmission selector lever in the PARK position while the ignition is on. The transmission selector lever position data is provided to the memory seat module by a message through the GMLAN Serial Data circuit.

There are somethings listed you are not familiar with , like GMLAN Serial Data circuit ,maybe Body Control Module software etc... GMLAN is a communincation network that the computers on the vehicle uses to share information , transmit commons etc... you can google it to read about it .

There are DTC'S - diagnostic trouble codes that can set in the module in control . Do you know what DTC'S are .

DTC Descriptors
DTC B1825 01: Driver Seat Recline Position Sensor Circuit Short to Battery
DTC B1825 06: Driver Seat Recline Position Sensor Circuit Short to Ground or Open
DTC B1825 5A: Driver Seat Recline Position Sensor Circuit Plausibility Failure
DTC B1850 01: Driver Seat Lumbar Horizontal Position Sensor Circuit Short to Battery
DTC B1850 06: Driver Seat Lumbar Horizontal Position Sensor Circuit Short to Ground or Open
DTC B1850 5A: Driver Seat Lumbar Horizontal Position Sensor Circuit Plausibility Failure
DTC B1860 01: Driver Seat Lumbar Vertical Position Sensor Circuit Short to Battery
DTC B1860 06: Driver Seat Lumbar Vertical Position Sensor Circuit Short to Ground or Open
DTC B1860 5A: Driver Seat Lumbar Vertical Position Sensor Circuit Plausibility Failure
DTC B2355 01: Driver Seat Front Vertical Position Sensor Circuit Short to Battery
DTC B2355 06: Driver Seat Front Vertical Position Sensor Circuit Short to Ground or Open
DTC B2355 5A: Driver Seat Front Vertical Position Sensor Circuit Plausibility Failure
DTC B2365 01: Driver Seat Rear Vertical Position Sensor Circuit Short to Battery
DTC B2365 06: Driver Seat Rear Vertical Position Sensor Circuit Short to Ground or Open
DTC B2365 5A: Driver Seat Rear Vertical Position Sensor Circuit Plausibility Failure
DTC B2375 01: Driver Seat Assembly Horizontal Position Sensor Circuit Short to Battery
DTC B2375 06: Driver Seat Assembly Horizontal Position Sensor Circuit Short to Ground or Open
DTC B2375 5A: Driver Seat Assembly Horizontal Position Sensor Circuit Plausibility Failure

5) Memory Seat Module is under the front of the driver seat , you could look under an see if all the connectors are fully seated.

The best diagnostic step would be to hook up the factory scan tool an see what the computer is seeing as far as inputs from the switch an outputs it's sending . I wouldn't suggest you take the seat apart an try testing electrical inputs etc.... unless you very familiar with automotive electrical systems an circuits .

There are 3 electric motors on the seat. One is forward and back, one is front up and down, and one is rear up and down. The switch changes the polarity back and forth to achieve the proper movement. I think the wire color for the forward and back motor is yellow with a white tracer and red with a white tracer. so if the switch gives the motor positive voltage to the yellow with a white tracer and grounds the red with a white tracer the seat moves forward. If the switch gives the red with a white tracer positive and the yellow with a white tracer ground the seat moves back. (or the other way around). So we can safely say it is in the switch.
Good luck and God Bless

on the 99 the front seats are identical. assuming there was little change in 2000 you unbolt both seats and move the passenger seat over to the driver side. while it is out, you set the sliders manually to be in the middle position and the passenger seat will be stuck there. If you can get light up inside there you will see a cable connector has released at one end meaning it will not release the dog to permit sliding so you may have to pull it manually with a vise grip in order to move the seat forward on the sliders to get at the bolt heads in the rear. unplug the battery before you unplug the seats.

Need to remove seat and check the drive cable from the motor to the affected side. May need to be reconnected or replaced. Make sure you disconnect battery as seats have side air bags in them.

I found this post area while looking for a way to fix my stuck 2001 Camry LE drivers seat. Sure enough, while engaging the seat motor (it could be heard making an initial clikc), I hit the front rails a coupel time prettysolidly with a rubber mallet. That fixed it!

Thanks to all for providing a quick fand easy way to get the seat moving again!

I had the same problem on my 2003 Toyota Camry. The threaded drive screws are what spin underneath the seat and cause the seat to move back and forth (same way a garage door opens or closes). When the seat gets all the way in the forward position, the threading on the drive screws ends, which causes the bolts connected to the seat to jam and get stuck. It should sound like the motor is trying to turn but it won't, it just clicks. Un-jam the bolts and rotate them one rotation from the all the way forward position to ensure your seat is reinstalled straight.