I wanted to replace the drum as one of the threads for the wheel lugs was stripped. Didn't realize the bearings are inside the drum. Can anyone give me a suggestion on how to remove it without damaging it? See attached.
Also, how tight should I make the 22mm bolt when reattaching?

You need to remove the lip seal by getting a screwdriver under it and prysing it upwards. You will damage it so a new one will be needed. The bearing inner race will then just come out. The bearing outer race is more tricky and will need to be pressed out using a suitably sized drift. The torque for doing the nut up is not very tight (about 4.5 lbs iirc) but I did mine up until the play in the bearing was taken up. Remember to rotate the hub as you are tightening it up and don't forget to grease the bearings or you'll be doing it again soon.

I have just done the wheel bearings on my 500L last week.

I don't have a press at home, so I removed the bearing outer bearings with a hammer and punch. The bearings outers have a lip that is a smaller diameter than the hub and with a bit of care, you can get a punch onto it and work the bearing cup out. It needs to come out evenly without cocking off to one side.

It is a simple job that took me about a minute each cup.

To reinstall the new bearing cups, I used a socket that was slightly smaller than the outer diameter of the cup and a hammer. Again, it has to go in evenly and all the way home.

Pack the bearings full of grease before you put them on, and put a bit in the hub and on the shaft too.

Don't forget to put the bearing cone back in before you put the new seal on!

Chris

Thank you both for your advice! I don't have a bearing maintenance kit so I decided to try repairing the thread in the drum, which worked OK. It will have to do until I can order a new seal for the bearings.