My 1989 190E 2.6L gas/auto has a problem.

If you pull the parking brake lever all the way up, the wheels still let the car roll back in Neutral. There is resistance in the handle, so I dont think the cable is broken, seems to me its out of adjustment.

I took off the rear wheels, but didnt see anyway to adjust the brake. I also tried to get the rotor off. Is it part of the hub? Do I need to take out the wheel bearings?

After I get the hub off, what do I adjust then?

Thanks.