This manual was very clear and complete, the prices can't be beat, great to have older manuals available!
Text excerpt from page 3 (click to view)
KRF-V7020D/V8020D/VR-307/309/357
DISASSEMBLY FOR REPAIR
1 x2
2 x2 2 x2 3 x2
4
4
1. Remove the 8 screws (1,2,3), remove the rear panel. 2. Connect the GND of the rear panel and the chassis, the GND of the mounting hardware and the chassis with 2 alligators clip (4)