Re: Changing Locking Motors on 166
No, no special tools are required, only screwdriver, several alen and torx keys, I don't remember the size. The biggest pain is to take the speakers covers off, but a little brute force and it would come off. When taking the door trim off, remember that after You handle all the screws, wired things, to pull it a little bit from the door to pull plastic rods out and upwards, as there are pretty tough metal clips near the window edge, keeping the whole thing in place.
Then rip the foil a little bit off, unscrew the inner handle, disconnect door pins, disconnect outer door handle and lock drum, unscrew the window rail, 3 more bolts and You have the power lock taken out. Connecting front door lock can be a little bit tricky, as You have to reconnect lock drum with the rest of the locking device - simply unscrew the outer door handle pull it out slightly and using long and thin pliers reconnect the mechanism.
And to the end of the story... Power locks in 166 seems to be dismantle proof and causing lot of trouble when refusing to work - the thing that fails in most cases are micro switches on the top of the mechanism or the wires that brakes. Using a little brute force You can try to dismantle the white lock cover, repair the switches and save a little $.