[Repeater-Builder] Dissasembly of msr 2000 continuous duty amp. How?

[martinfriedman67]

Our Amateur radio club's Motorola MSR 2000 continuous  duty amp needs repair. I 
cant figure out how to remove the amp board from the heat sink. I removed all 
screws from corners as well as the transistors. It seems to be held by the 
center,  just below the tall air variable cap. I tried heating the  solder in 
the area but, no joy. I don't want to crack the board. The drawings in the 
manual I found here do not show even the screw holes.
Thanks in advance, 73, Marty (WB2BEW)