2003 BMW K1200GT transmission output shaft seal replacement

BMW K1200GT transmission output shaft seal - Before removing the old seal, measure the depth of the front face of the seal with respect to the surface of the gearbox housing.
I drilled a small hole into the face of the seal, drove a drywall screw into the hole, not too deep, and then pulled the seal out of the bore.
The bore is deeper than the width of the seal. So it is critical that you DO NOT push the new seal into the bore until it bottoms out. The seal will not bottom out parallel to the front surface of the gearbox housing. You MUST push the seal into a prescribed depth. I designed this seal installation tool and then 3D printed it to ensure that the seal is uniformly installed to the correct depth and parallel to the face of the gearbox housing.
The same procedure can be completed for the input shaft seal. This seal has a smaller diameter and is a bit more difficult to remove. I also designed a different seal installation tool for this seal. The tools are NOT the same. BMW sells these tools for a few dollars (maybe $100 - $200???).