I totlly agree, it's not a DIY job.
I have tackled just about everything on my 126, but couldn't whip that rear bearing.
I went so far as to buy the big "castle nut" socket that is required to loosen the bearing retainer. With an 18 in" breakover bar and a 3ft cheater, and two of us big guys hanging on the end - we couldn't budge that retainer nut.
My big impact just bounced off also.

DG