All instructions I found about upgrading the RAM are to remove the CPU tray, then work from there. But a bit funny thing is, the metal frame around the CPU tray of my Mac Pro 5,1 is damaged and getting loose and obstructs the tray, so a bit of prying is required to get the tray out. Hence I wonder if it is safe to just remove and install the RAM while keeping the tray in. There seems to be enough space to work out in a single 5,1.
Of course, the system will be kept unplugged during the upgrading procedure.
Of course, the system will be kept unplugged during the upgrading procedure.