That shouldn't be a very difficult mod to do. You will just have to buy a combo drive off of ebay or somewhere, disassemble the powerbook and remove the old one, then put the new one in place. I know that I am probably stating the obvious but thats about it. I looked to see if we had a guide for disassembling the powerbook and we don't, so I can't really help you here.
It will provide you with some info on how the computer is built and you should be able to locate everything that you need from that. The should hook up exactly the same, so there shouldn't be any problems there.
Be sure to take plenty of pics and document your mod so that you can post as a mod guide on macmod.
"Fix it 'til it Breaks."
Jacob - EiC & Director of Technology Mac Pro Quad 2.66 - 4GB RAM 160 GB SATA RAID 1 - 650 GB Storage Quad 19" Widescreen LCDs Accessorized to the Hilt
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