Thorens TP 16 counterweight sagging

I have a Thorens tD 160 with TP16 arm (mk I i think) a tenant left behind after being evicted. The turntable was subject to moving abuse, the counterweight was on the arm. The outer platter is missing, but the inner platter appears to have not bent the spindle. i haven't put a dial indicator on it or the drive pulley yet, so i don't know if the unit is salvageable.
The tube the counterweight slides on droops down about 2-3 degrees. i'm worried the arm tube is bent, but i don't know how to get the larger tube off to check.

Is there a guide for disassembling and cleaning this arm?
 
Thank you, i have looked over that site pretty thoroughly. They show the arm completely disassembled, but don't describe the process to get it there. i think i understand how to get it apart, but there is always some detail that is not obvious unless you already know about it. i am not clear about how to remove the large tube, that the counterweight fits on, from the main arm tube, is there a screw inside the tube, or is it just press fit over the rubber isolator?