Change Bremdisks and Blocks at the MAN L2000

Hello guys, need some help! Would you like to change the windows and blocks of an L2000 MAN. Unfortunately I am facing a problem with the dismantling! Satell down the about 10 screws solve clear but then? Must the 67 mother down in the middle? Have tried to solve them already! but didn’t succeed!! Is there a trick? or does it have to be destroyed? Thanks for hints and tips. MFG Martin