e34 touring: headliner removal

[Hozay]

Hi there
I'm currently commissioning a full rebuild of the twin panel sunroof of my 94 e34 touring. Curious if anyone has any idea how to remove the rear panel headliner, so as to access the hardware underneath and proceed with removing the panel altogether.
Does thi even need to be removed as part of maintenance/rebuild? If so, anyone have any insight?
Cheers in advance!:)

[shogun]

22 pages, German language, but enough pics to understand it without understanding German
http://www.e34-welt.de/tips_tricks/dshd.pdf

[Hozay]

Man, where do you find this stuff? Sure it's in German, but those pictures are pure gold! I'll go at it again. Thanks a bunch!