Drilling out the broken bolt:
The threads didn`t survive the removal so I drilled them through, tapped and inserted two helicoil threads in.
This is the rebuild kit I`ll throw in. Not a bad deal for $25.
I also invested into this ($8):
Works pretty well for the bearing on the back.
For the front one I needed some additional tools and I had to remove the outer race:
Leftover of the old slip ring now can come off:
Reassembly is coming soon.