15" PowerBook G4 Logicboard

So my old 15" Aluminum G4 PowerBook (1.25) isn't feeling well. The monitor has a bad checkerboard pattern which also transfers to other external monitors when I plug them in. From what I can gather, this means the video card is bad which means replacing the logic board. The images on the monitor are bad enough I can't see what I'm clicking on or what pops up. I've replaced the AC/Power/Headphone/Sound card on this machine so essentially I've had it stripped down to the logic board before. It's not a tough job, except separating the top-case, so I'm not afraid to go "in" again on my own. I know this machine isn't worth much but I do need to retrieve the hard drive contents so I'm willing to pay $60 for a used logic board and investing some time. My question is this: If I replace the logic board, will I lose all of my contents on the hard drive (i.e. music, pictures, videos, and documents)? In other words, will I have to re-install the operating system essentially wiping clean my hard drive? I don't have the OS X install disc anymore either...

Instead of messing with replacing the logic board on a computer that may not survive the transplant.... just remove the hard drive, place it in a USB carrier, hook it to your other machine and extract the data. You can pick up a USB carrier most anywhere for less than $15.

But for $60, he can get his stuff, AND, he has a nice, working backup laptop.