Any ideas how to get to the bearings?

I have completely dismantled the machine and drum but cannot loosen the
bolt off the rear of the drum that holds the belt wheel on. I think it
should be loosened anti-clockwise and probably needs an impact to get
started?

I'm worried about shearing the bolt head off.

My other option is to buy the entire rear part of the drum
pre-assembled but this is appx £80 as opposed to a tenner for the
bearings!

help greatly appreciated