Installing Internal HD in G4 PowerMac Mirror Drive


I have an 80GB external Iomega drive in which the power supply stopped working, so I want to install as an internal. I got the casing off, and tried to install following Apple instructions, but can't seem to get the little plastic tab to release the rear drive for installation. :(

I am a novice at this, and am afraid something is going to break if I lift the tab any harder. Any suggestions? Once I do this, is it pretty easy sailing? Thanks for any suggestions as I am a do-it-yourself gal and don't want to pay someone to do this.

realgal :)
I'm not 100% sure where you want to install it. Do I get it right, that you want to install it next to the pre-installed drive in the ATA100 cage? (Near the back next to the processor)

If so, you first have to remove a screw on top of the cage, that holds it to the case. Only if that is removed, you can release the cage with the plastic tab. Maybe that helps already, otherwise feel free to ask. :)