Remove all the screws around the lip on the back, and both screws on the left and ride sides. You will need a T20 tamper-proof security Torx bit: https://www.amazon.com/gp/product/B002HUL6PY/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

Slide off the case to the rear.

View the youtube video in the description to get an understanding of what is going wrong and where all the parts are. You do not have to unscrew the mechanism. Figure out where you are going to attach the hook. On my model, there is a flat 45 degree section at the end which is suitable. On other models, the curve of the interior cavity wall opposite may not make that possible, but there should be somewhere that works.

Engage the hook and hold it to your proposed mounting location with one hand, and test the door latch with the other. It should open and close securely, like new.

Use superglue and accelerator to mount the base of the hook to the wall. Let it set securely, there will be a lot of pressure trying to pop it off every time you open the microwave. Epoxy might work if you prepare the surfaces very carefully, but it tended to fail for me.