If its similar to mine it should have three plastic bits to pop off on the bottom that hide some screws. Then there is a screw in the bottom of the "deep" door handle and one hidden behind the door handle opener. The section that the window opener is on should pop off with a flat head screwdriver in the right spot (might have a notch where to pry from?). Then if I remember correctly the rest of the door trim can be pulled off, its only held in by small plastic clips. Ohh and pop off speaker cover too.
plastic clips round the outside Ease round with your fingers till you find the first one then keep working round till you get them all. It is easy to break the hardboard backing so be carefull. The door handle switches and ash tray will be screwed in place and help hold it on.
Sanding your knuckles before starting work can help. That way you cant skin them
What kind of wing mirror you got? There are 2 kinds. the early Mu's have quater windows in the doors. to get to there wing mirrors you have the window fully up and reach way up to the top of the door frame to get at the two bolts holding it on. the newer ones don't have the quarter mirrors and some have mirrors you access by popping a small triangle of plastic off at the very front of the door panel.