my rear right door wont open at all. tried opening from inside but no luck. any suggestions? its a '90 740 Turbo...

 

This is from the Turbobricks Forum:
Remove the trim which holds the speaker and unscrew the locking button, then there is one or 2 screws to be removed. Pull the remaining trim up until it unlatches then pull it outward to remove it. Pull up the locking control as far as it goes then look through the hole so you can see the locking mechanism and watch the little part which moves sideways when you try to lock and unlock it. Then push it towards the inside of the car (you may have to "wriggle" it a bit) while pulling on the lock switch. The door should then unlock and you can open it. Remove the lock with an allen key and detach the control arms and thoroughly lubricate it with some oil/ grease/ or equivalent. You may have to remove the seat by pushing it back hard then pulling it up at each side then sliding it out, in order to remove the door trim