Warning: Removal of the front part of body can change of flange focal distance of lens mount

"The any procedure with Remove the front part of body can change of flange focal distance of lens mount and can destroy of adjusting of lens mount of camera.
That's why, After you remove and put back of the camera face you will need check of flange focal distance of lens mount with special mechanical measuring tools or with auto collimator and test lens with high precision 61.00 +/- 0.01 mm."
- Olexander