With great diffiuclty... Fromt what I rememebr, the cartrige holder (upper casting) and the 'base pan' were nver intended to be separated. You can easilty remove the top covers, the PCBs, the front panel, filters, rear panel/PSU, and with a little more work remove the spinlde motor, head positioner and spindle (note that you don't need an alignment disk to set up an RL, any disk pack will do, but you will need a 'scope). I hope that will be enough (if so, I can try and talk you through it). If not, well, I think the base pan is pop-riveted on, but there may be sealants too. -tony