Originally Posted by E46CT

I've taken these mirrors apart about 10 times so far? So they're really easy to disassemble. If I'm not mistaken you can fix this standing outside the car. Remove the glass (just pull from bottom with fingers, it clips in. Then there's philips screws on the inside that hold the outer halves together. total 3 pieces. Just ask the dealer if they sell the painted outer half, the top piece, and the inner piece. If so, you can fit them all to the inner core/frame and call it a day.

If you can only get the entire assembly, it will be expensive unless you go ebay. and even then it's expensive but you do need it. in that case, you'll need to remove the door panel to access the 3 bolts/nuts holding it to the door. but that's easy too. i made a thread on removing the door panel. and yeah you'll need the glass too of course. i think there's BSM and non BSM. IIRC all are heated. then i believe some mirror housings have the camera cutout. not sure which options your car has but you'll need to match them all.