I finally managed to replace the shaft in the brushless outrunner motor I have for my Vosper MTB. I had been trying to drive the old shaft out by using a hammer and a nail, but that didn't seem to move the shaft a bit so I decided to use a vice instead. That worked well
I placed a few large nuts at the end of the bell so I could drive the shaft into the void of the nuts. Then I used a nail to push the shaft into the bell. The largest problem was to keep the nuts and the nail in place. So I fixed the nuts to the bell by some tape. Then I used the vice to press the nail towards the shaft into the bell. That worked quite easy.
Inserting the new shaft was even easier. I put the new shaft in place after removing the nuts. Then I used the vice to push the new shaft in place.
I replaced the shaft because I needed a different shaft diameter (3.17mm) that fits the joint that connects the motor to the propeller shaft. Replacing the motor shaft was the easiest way to make that work.
Merry Christmas everyone