There are two ways to adjust the BMW E36 brakes on your car.
Easy: Jack the rear so you can feel the internal drag of the mini-drums as you go. Remove the brake handle boot run the nuts down on the threaded cable ends. You can also stack additional washers under the nuts to remove more slop/play in the cables to a certain extent. This method may not give you the friction/pull you need to do the the job.
See pic===>
http://www.101projects.com/BMW/Proje...s/DSC03766.JPG
Harder: Make the adjustments at the adjuster under the mini-drum aka rear rotors. See instructions====>
https://www.pelicanparts.com/BMW/tec...Adjustment.htm