drivers it's something that you may have to do one day, luckily it's a very easy task.
There is a rubber boot over the adjuster (manual adjustment only), this should
just pull off revealing a large nut with 4 indents. Use a pair of pliers and unscrew
the nut (large red circled in the picture below). Open the door look for the two
T20 Torx head screws (2 small red circles below), remove them.
The whole cover will now feel loose, it needs to be pushed up and away from the window,
it also helps to push the adjuster arm out of its retaining hole.
Once the cover is off you will see 3 more T20 torx headed screws on hollow spacer washers. Remove them and store them safely.
Hold the wing mirror as you undo the 3 screws to stop it from swinging down and damaging
the door, once the last screw is out, the wing mirror can be pulled away from the car.
Removing the wing mirrors leaves a big hole so don't leave the car out in the rain.
This is the manual adjuster lever, each cable is colour coded
When putting the wing mirror back on, ensure that the foam backing is put on straight or it may leak. Test the mirror adjuster to determine which way round it should sit in the cover.
Removing the mirror glass
This is another very simple exercise, adjust the mirror glass as shown, get your
fingers underneath and pull. The glass shouldn't break, it never has for me.
The mirror and base should unclip from the adjuster base with very little effort,
try not to pull too close to the edge of the mirror as it may break.
To replace the glass, place the glass and holder correctly against the adjuster base and push
with the ball of your hand in the centre of the mirror. It can take a scary amount of force to get
it to seat properly and you may have to try getting one side on and then the other. When it does
seat in properly you will know as you get a satisfying click.