1. Thin piece of plastic, or flat screwdriver with tape wrapped to protect from any damage.
2. Plastic Squeegee
Position the mirror so that it exposes the top left or top right of the mirror (depending on which side you're working on) and use the screwdriver or something plastic to unclip the white clip as seen below:
Using the plastic squeegee, start from the top of the mirror blinker (as shown in the picture) and carefully apply pressure from the bottom, then from the top, until it start disengaging.
I wrapped the mirror caps in gloss black vinyl: