I think you just need a phillips and flat head screwdriver. The screws in the back allow the top of the case to come off. the metal shelf holding the cdrom , HD, and floppy comes off with one or two screws. There is a plastic piece holding the PS in, you slide that out the PS should come off. I think the motherboard has a screw or two holding it in, remove those and push down one some plastic retainers and it would slide out of the case.

Not that much to it.