I haven't tried rear bearing replacement on my coupe, but did it on the 325i my daughter drives. That car had 160kmiles on it.
On the 325i, rear bearing removal was an all-afternoon session, upside down and under the car, beating on a driver, in my case a 2 foot long bit of 1.5" galvanized pipe. I used a 2.5 pound sledge, with a friend backing up the trailing arm with the head of my six-pounder. I sledged my hand a couple times but thankfully never between the driver and sledge. The bearing is destroyed on removal of the hub and stub axle. The inner race came out on the stub axle and was removed by using a dremel to groove it, then a cold chisel to crack it off. That part was not difficult. The outer race is really really stuck in the trailing arm. I only did one side, the other side is still quiet thousands of miles later. My consolation was that it made quite a difference.
I later had a conversation with a retired ex-dealer tech about the job. His words were that sometimes those bearings just fall out into your fingers, but some took pretty much the level of force I used. He of course always had access to the correct special tools, air impact, puller, a lift, etc., and even then some needed major force.
Were I to contemplate this project I'd want to be certain it was needed. To do that, I'd lift the car, disconnect the half shaft and observe how the wheel spun, how it stopped, and use a mechanic's stethoscope if I had one or could rig something up.
But hey... YMMV!
