I just had the occasion to repair a microwave oven door with a similar problem . The Maytag unit in question is a over-the-range type and the latch mechanism would not latch. To fix mine I took the door off and laid it down on a smooth surface on top of an old towel. The back of the door has an outer frame of plastic that is able to be popped off by carefully using a small screwdriver. It took me several times around gradually getting it to move and it finally popped off w/o breaking anything. When it is out of the way you can get at the screws holding the door handle in place.
In my case the sliding part that is the latch/fingers was able to slide OK but a tension spring was no longer connected to it. The slide which is made of plastic on this model has a section where the spring is supposed to hook into and had broken off. It is very small and thin and prone to break after many cycles of use. Since Maytag will not likely sell this small part I took the slide out and drilled a small hole thru the plastic just big enough to hook the spring thru and as close to the original location as possible w/o weakening the part. It worked very well and a $100 repair job was avoided.