Good evening, I have the same problem with my X5, I thought I would just stroll over and open the passenger lock but low and behold, there is no lock on that side, or on the rear hatch either!
I can tell you in my case, the lock cylinder rotating piece had broken (the inner rotating part) I found the fix kit (regulatorfix.com) and purchased it. Its on the way! I tried to salvage one from an X5 at the wrecker, it too was broken. with no key I couldn't test it! however, I used it as "practice" to figure how to repair mine! the little rolled pin simply pulls out, then the u shaped round slides out past where the pin was, then the rotating actuator rod comes off and the spring shoots out after! I found that once I had removed the lock mech, I was able to lock and unlock my x5 with a screwdriver!! I pulled out my key cylinder, after inserting the key and turning it to unlock, and cleaned and serviced it, waiting for my new lock repair kit to arrive!
at least its an easy part to remove, and the door panel can stay put!
Best of luck,