Rockwell Automation 8520 9/Series CNC Integration Maintenance Manual Documentation Set - Manual (Page 772)

Section 15B
Replacement Procedures
15B-16
3. Use this figure to find the release tabs for the flash memory.
4. Press the raised lever on the left and right tabs at the same time to
release the SIMM module. As the module is released, it turns
slightly.
5. Remove all SIMM modules from the board. These modules contain
the PAL and AMP information for your control. You may want to
label these modules before storing them. You will need to reinstall
the modules when you receive the new or repaired processor board.
6. Remove the 10 screws indicated in this figure.
7. Remove the processor board from the component enclosure and lay it
down on a clean surface with the connectors facing up.