Hi,

Try this page. It's a great resource that provides instructions on getting to any component in a slot-loading iMac.

http://www.scribd.com/doc/103447/iMac-G3-Disassembly-Guide

Just keep scrolling down or do a search until you find the part in the document that covers hard disks. (It's about 1/6 down the scroll bar)

EDIT--Wait a sec, you said iMac G4 in your first post. Is it a G3 or a G4? (iMac G4s look like a hemisphere with a flat monitor sticking out of it on an arm, and G3 models look like the ones LCGuy pictured.) The document I linked to covers instructions on a slot-loading iMac G3.

-Apostrophe