I have a small pool pump, how do I remove the impeller. I did remove the phillips screw, am stumpped now!

Depending on the pump you have to separate the motor from the housing bust removing the bolts. Once the expelled is exposed, remove the cover and the back end of the motor housing the electrical wiring. You can access the shaft of the motor and hold it in place with a small box wrench. Than spin the expelled off counter clockwise. Replace the melchanical seal and reinstall the impeller. Replace the seal for the housing and reinstall the housing to the motor. Fill the pump with water again and turn the lower back on

Turn off the system at the breaker,
Undo bolts for housing and separate the motor from the pump to access the impeller. Some styles of motors have a screw that is reverse threaded holding the impeller in place, if it has one , remove the screw. Once you have access to the impeller you can use a big pair of channel locks to turn the impeller. Take off the back cover of the motor or remove the plastic or metal cap that is covering the shaft. Use a wrench to hold the back end of the shaft as you unscrew the impeller.

i think they screw on and the screw only locks it in place

To get to the Impeller you need to remove a series of bolts, or a large clamp, that holds the two halves of the pump together. Once you do that, if their is a diffuser (housing that goes over the impeller), remove it. To remove the impeller, you need to lock the motor shaft. You can do this a couple different ways depending on the motor. There will either be a small cap that grants access to the motor shaft on the back of the motor, or you remove a larger housing that grants access to the wiring and other components in the back of the motor. If it's the small cap, then you can hold the shaft with a wrench. If it's the larger housing, then you can slip a wrench (probably 7/16") under the thermal overload switch and onto the shaft to lock it in place. Now you can unscrew the impeller. Check to see if the impeller has a screw in the center. If so remove this first. It will be reverse thread. The impeller should spin off counter clockwise. If the impeller is very tight, be careful not to damage it. If you don't have an impeller wrench, I strap wrench, or very large locking pliers with a rag around the impeller works well. Hope this helps. If you need further assistance post a reply in the comments, and don't hesitate to leave a good thumb rating if you found this helpful. Thanks, and good Luck!

After you have the pump broken down. Check for a screw in the center of the impeller. If it has one then you will need to remove it. This will be a left handed screw. If that is done then you will need to remove the back of the motor or the small center plate on the back. Then the shaft will accept a wrench to hold it with. Then you should be able to unscrew the impeller with water pump pliers or a large basin wrench. The brass threads on the impeller will kind of stick to the steel of the shaft so it is just a matter of breaking it free, then it will spin easily.
I usually put a screwdriver in the left side of the impeller and give it a sharp smack downward with a hammer.
There are two methods, good luck.

Disconnect all power. Remove the six bolts holding the seal plate to the wet end. Remove the two small allen screws to remove the diffuser. Remove the dust cap from the end of the motor and secure the shaft from moving. If installed, remove the Phillips head screw in the center of the impeller by turning clockwise (left hand threads). You can now remove the impeller by turning counter clockwise, note that you may need an impeller wrench to remove it and a specific tool to hold the shaft while you remove the impeller. Once the impeller is off you can remove the four bolts that hold the motor to the seal plate. This process just needs to be reversed to re-install but you will need a new shaft seal (PS-1000).

First, separate motor and pump. Remove back cover of motor. Drive shaft of motor either has a slot on end for a large screwdriver or a flat on it for a wrench.(usually 7/16) Hold shaft and unscrew impeller.