Unplug the GE microwave from the electrical outlet and remove the screws from the metal backing on the microwave. On GE microwaves, there are eight to 12 screws holding the backing in place around the perimeter.
Pull the metal backing away from the rest of the unit to reveal the hardware components of the microwave. Do not touch anything other than the fuse. If you knock any wiring or connections loose, the microwave may fail to work once the fuse is replaced.
Find the end of the power cord where it disappears inside the microwave. The box where the power cord disappears is the location where you will find the fuse. The fuse is a cylindrical glass object with metal ends. A burned fuse generally appears dark in color.
Remove the old fuse from the GE microwave. To remove the fuse, grasp it gently between your fingers and pull it directly toward you. The fuse will pop free from the chamber.
Hold the new fuse up to the chamber, lining the top and bottom up with the clasps that hold the fuse in the microwave, and push the fuse into the chamber. When the fuse is in place, pull back gently to make sure the fuse holds.
Return the metal backing to the microwave and replace the screws to hold the backing in place. Once the unit is back together, plug the microwave back into the electrical outlet. If the digital display on the microwave lights up, the microwave is probably back in working order. To test the microwave, place a bowl of water in it and turn the unit on.