Turn off breaker, remove all screws { 4 on mine } inside oven door holding oven and microwave to kitchen cabinet and slide oven assembly out of cabinet {on to a temporary shelf of {4} 5 gallon buckets/plywood/bricks/shims that I made on the floor atop a scrap of carpet} just enough to access the side and rear screws of microwave's protective metal housing, then remove a total of 16 screws { there were 2 screws just inside top of "opened" microwave door that were holding top flat silver metal panel affixed to the front stainless trim panel, 2 screws per side on the black protective metal housing, 6 on cord protector to then access all 4 on rear of black metal housing} and remove flat silver metal panel then cord protector then black metal housing, remove broken plastic "door release lever" by bending a metal keeper on outer side with fingers and then carefully flexing/bending a black plastic keeper at inner side with fingers or screwdriver ...noticing that a small portion of the new release lever will need to slip behind a stationary white plastic tab just above release lever near the far end of lever, the new lever must be inserted like a dowel in a hole at 2 points while rotating it slightly to allow it to slip behing the stationary white plastic tab, after new lever part is installed bend small metal keeper back with screwdriver, check to see that microwave door opens properly, reinstall all screws and panels in reverse order, slide oven assembly back into kitchen cabinet, rescrew oven to kitchen cabinet, turn on breaker, reset clocks.
I hired a repairman who opened the microwave door to begin with using a slimjim type device { who later would not return to finish the repair } if your door is closed as I expect it would be...I beleive you could bend the flat silver metal panel upward if the 2 front screws inside door aren't accessible then after the repair and the door is open the silver panel could then be removed and hammered flat where you bent it.
Replacing the part itself only took a minute or two but the entire job took me hours because I had to do it by myself and was concerned about the weight of the unit....the unit is heavy and very "front heavy". { 2 screws were odd size allen screws and I used pliers on them, the rest were phillips and square drive }