I'm assuming the dryer is not heating.

Have you checked the circuit breakers for the dryer and the wall outlet for 240 VAC to the dryer?

Have you performed the troubleshooting according to the wiring diagram?

In order to disassemble the dryer:

Using a putty knife push the clip on each side on top of the front panel to release the top panel.

Lift the top panel and remove the screw on each side of the front panel and wires from the door switch, and remove the front panel.

Remove the access panel on the back of the dryer and draw the picture of the belt goes on the motor pulley. Remove the belt from the pulleys.

Grab the drum with one hand from the back and another hand from the front, lift it up from the back and pull it toward yourself to release it from the rear bearing and pull it out.

Here are the breakdown diagrams and Replacement parts for FRIGIDAIRE FDE336RES2 | AppliancePartsPros.com

Gene.