The controls are on the glasstop and no way to access them from below, so the glass top has to be removed by removing any straps/braces from below and raising the rangetop housing above the counter height.
The foil tape connecting to the downdraft ductwork will need to be removed. Make sure you have foil tape to reseal this connection.
The black foam tape between the cooktop housing and the countertop will need to be separated with a putty knife. Be sure to have the 1/4” low density foam tape on hand for replacement.
Remove the 6 knobs by lifting them upward and then lift the housing above counter height.
The loosened housing can be supported by two pieces of 1x2 that straddle the opening. The sheet metal screws around the perimeter are easily removed and a putty knife under the glass should release the glass. Once the glass is removed, you’ll see an electrical control box with the 6 switches. The fan switch is held in place with two screws. The switch can then be accessed from the side and replaced. Just note the 4 colored wires and move them to the new switch. There’s a 5th contact that’s unused.
Reassembly is straightforward but you’ll need to remove any remaining foam tape, clean the underside and the countertop before applying the new tape.
Could not find any videos thru GE or thru YouTube for a drop in cooktop. After trial and error, found out the following:(1) easier to repair when glass is place down on work area, (2) only remove screws on housing that are closest to glass top. These will allow the glass to come off. The remaining screws hold burner brackets in place. (3) burners are held in place by two pins apiece. Further, each pin goes thru a spring which pushes burner flush against glass. By having glass down, it is much easier to position burners and ensure springs stay in place. Finally, when replacing the burner, make sure to put the flanges (thru which pin goes thru) in same places. GE burners have numeric marking at flange positions so this is easy.