He said it's a G4 Powerbook. It woudn't be that difficult, and I sure as hell wouldn't pay someone else to do it, unless I was under warranty anyway, and I wouldn't have to pay then...
Go to
http://www.ifixit.com/Guide/ and check out the step by step instructions (with pictures). If you still feel you can't do it, then pay someone.
I just read the instructions for my G4 Powerbook (Al 15 inch 1.5GHz) and other than keeping the screws in the right places for reassembly, it looks pretty simple. Just make sure you have the right tools... they even tell you which ones to get and you can buy them from that site.
(#0 Phillips screwdriver and a T6 Torx screwdriver, and if possible, a 1.5mm hex wrench in my case...)