Yamaha A3000 Owner's Manual page 315

Switch off the A3000 power, and unplug the power cord from the wall outlet.
2.
Remove the screws holding the A3000 top cover in place.
3.
Set the A3000 upside down on the workbench and unscrew the 6 screws along the sides
of the bottom (see drawing). Then turn the A3000 right side up again and unscrew the 3
screws along the top. Then unscrew the 5 screws holding the cover to the rear panel.
Bottom
4. Hold the two sides of the cover and slide the cover straight back (over the rear
panel) and off.
Top
Rear panel
Installing SIMMs
Appendix
313