Shift ball bearing down by 1-2 mm

First of all I have to apologize, because I cheated a bit. I am asking for a Dremel 3000 not for a Dremel 4000. However, the Dremel 3000 is not in the database yet and I think there are no big differences concerning my problem.

So, I have a more or less unused Dremel 3000 with the lock pin not working. I opened up the tool and noticed, that the pin can never enter the designated holes, as the shaft is a bit dislocated in the case.

As far as I can see, the location of the shaft in the case is only determined by a ball bearing fixed to the shaft. So I would need to move the ball bearing 1-2 mm "downwards" (to the motor) in order to have the pin enter the holes.

Find some photos here: https://nextcloud.yeara.net/s/gyAXmmRGb7...

However, the bearing cannot be moved by hand.

Can you give me some hints how to move the bearing without damaging the tool?

Thank you in advance!