You will only need a screwdriver for this task and a pair of pliers or a T6 Torx Screwdriver to remove the side anchors on the drives... There are many tutorials on here that can assist you. Links to cheap supplies: Would need to know which model (late or early) you have to be able to give you a link to the how-to disassemble. Hope This Helps :)

Couple of options to try: 1) Reboot system and hold down the trackpad button (under the track-pad) during boot-up this should cause the drive to eject anything still left in the drive... Option 2 (Not sure if it will work on the older G4's) Eject a disc with Open Firmware commands Follow these steps: Restart the computer. Immediately after the startup sound, press and hold the key combination Command-Option-O-F. Release the keys when you see a white screen that says "Welcome to Open Firmware." At the prompt, type: eject cd Press Return, then wait a few seconds. The disc drive should eject any disc that is present, and "ok" appears behind your command when the action is complete. Type: mac-boot Press Return. Hope this helps :)