The DIY turned out to be anti climatic. Started off well. Jarance was able to open the side mirror with no problems. Only to discover that the previous owner removed most of the original motor parts and put in a manual type side mirror mechanism. So until I get all the necessary missing parts, I'm afraid it's still no go even with the new motors. Bah! Stupid previous owner!
Anyway, many thanks to bro Jarance for taking a Saturday off to help a fellow BMW owner. I got served with coffee as well. Very hospitable of him. My gratitude to him for attempting this repair.
Haywire, If you do find out that the E39 side mirrors uses the same motor, then i have 2 for sale. Haha.