How do I raise the cooktop on my Frigidaire Gallery Model #GLGF377ASE . I need to access the burner orifices.

look under the top for screws holding top on

Hello. There is *no* pilot on this range! You have a glow bar for both the bake and broil functions in the oven. The bake glow bar part number is (#19) 316489402(see pic 2). The ignition module(that provides the high voltage for the spark posts at each of the surface burners is (#8) 316262400. The ignition harness(that has four ignition switches daisy-chained together is (#3) 316580615. The sealed burner for the LF and LR is 316558300(quantity 2). The RF burner is 316438600. The RR burner is 316438200.
RF orifice/ignitor assembly 316536614
RR orifice/ignitor assembly 316536610
LF orifice/ignitor assembly 316536602
LR orifice/ignitor assembly 316536600
BURNER HEAD SCREWS (QUANTITY 8) 316540900
LP CONVERSION KIT (#47) 316542414
If you are hesitant about the disassembly on the range, I strongly advise calling for service--The cooktop must be removed to exposed the ignition parts. This is accomplished by releasing the burner heads from the cooktop. The mount screws on the burners are notorious for seizing and the heads breaking off on removal. If this happens, the orifice/ignitor will have to be replaced for every burner with which this occurs. It can be expensive! I hope the diagrams and part numbers help you!

The switch controlling the burner is just a voltage controlling unit (rheostat). It needs to be replaced

If you need further help, reach me via phone at https://www.6ya.com/expert/steven_a67ead41eb5fc62a

You will need to replace the surface switch. Here is the part to order.
Keep me posted.

If it's a standing pilot (on all the time), rather than a spark igniter, just hold a match in front of the pilot orifice and it should light.

Hello- You got lucky and only have one stuck, unfortunately you will need to order a few more parts. The only way to get the venturi out is to drill it off, drill it down enough that you can get the burner around what use to be the nut portion of the venturi. You will also need to get the orifice holder that the ventrui screws into under the cooktop. These parts are pretty cheap. You could try to put some LIquid Wrench around the ventrui overnight but be sure not to try to force it out too much because the gas supply tube to that burner can get creased if the orifice holder starts to turn... What works best for me to drill the venturi is a countersink, preferably for metal, which has it's largest diameter bigger than the outside of the venturi. Get some cutting oil and start drilling, the ventrui's cut pretty easily but take your time and try not to damage the burner. Once you get down real close to the burner you can try to carefully pry the burner over the remnants of the venturi. Good luck, hope this helps. Best regards.

To remove the main top first remove the grates,
burner caps and burners. Using a ¼” socket
wrench or nut driver remove the mounting
screws at each burner orifice assembly.

Insert a putty knife or similar tool between the
main top and manifold panel near the outside
of the front corner. Push the putty knife toward
the rear to release the maintop mounting clip.
Repeat for both sides.

When the mounting clips are released the front
edge of the cooktop can be lifted. Make sure
that the orifice assembly does not bind in the
cooktop when raising the top to remove it from
the range.

Lift the front of the cooktop and pull forward to
disengage the back edge from the rear hinge
bracket. The cooktop can now be replaced by
reversing the previous steps.

See Manual at http://www.electroluxtopservicelatam.com/image/Manuals/Services%20Manuals/Preparation/Cooking/30%20Inch%20Freestanding%20Gas%20Ranges%20(5995440277).pdf

take knob off and check the middle is not split and hence not turning the shaft

No adjustments.  You will need the correct orifices.  Contact maytag to get the correct ones.  They should send them to you for free.