Well, you won't be able to exert downward pressure on the wheel because of the configuration of the MB-40 but you can certainly exert considerable lateral pressure. Try that. Be sure you're turning in the right direction. It appears you stripped the splines of the plastic wheel so the MB will have to be disassemble to remove/replace the wheel. Highly doubtful you stripped the metal threads of the stud or tripod mount on the body as the plastic splines are the weak link. I'll speculate that the repair is pretty simple; remove small, phillips screws in top-plate of MB to access the wheel.