Have you pulled the microwave out from the unit yet?
Also can you post the service number. If you open the door there will be a barcode with the number under there. It will start 85 can you post this please. But you need to prefix it with an A otherwise it gets crossed out.
Ok usually they just sit in there so try pulling it out. But if this doesn't work there may be screws both on top of the frame and at the bottom.
So if theres a cubboard above the microwave open this and look on the top of the front trim in the corners and see if theres a screw there.
Do the same to the bottom and then you should be able to pull the microwave out from the unit.
Try that and see what happens and let me know.
Ok you have the other version that is secured differently.
What you need to do is see them allen key screws you need to loosen them as they when you do it release a bracket at the back so when they are lose enough you can then pull the microwave out.
So if you can find an allen key that will fit and loose it and this will allow you to pull the microwave out.
Once out you will then be able to see if theres a plug behind there or weather its wired directly into a socket.