Changing the door mirror's or colour coding them is a very popular mod...Later cars had this done at the factory but the early cars where all Black! To remove the mirror's for painting is quite an easy job

1 Remove the door card completely

2 Remove plastic mirror cover from inside the car (see pic 1)

3 Remove the three + screws holding the mirror on and unclip the multi plug. (see pic 2)

4 Remove mirror from car and Paint!

Pic 1

Pic 2