What all the others said. If you just want to get the 9500's motherboard out, it's no different to most other desktop machines - take the case off, take the cards out, disconnect the HDs and power connectors and all... And it's no worse than other machines in that way.
The big issue with it is if you want to add a couple of RAM sticks - you HAVE to take the motherboard out. For one of the most common acts inside a computer (apart from PCI cards I suspect), having to take PCI cards out, disconnect HDs, disconnect all the rear cables, disconnect the front panel wires, sound, floppy etc... is just a touch mad.
Dana
(I say HAVE to, despite having changed RAM myself by swinging the motherboard up out of the way, but I also dropped it like that - not the best thing for a long machine life!)