If the mouse eject trick doesn't work, in which there's a chance this will be the case because of Open Firmware's inability to open the drive, then you will need a paperclip to the small eject button on the side of the drive, same as on the iMac G3's.

I can assume it's still there, unless Apple took it off (which case we can assume Apple has decided to make this hell for us).

Always a shame to hear the drive go... but moreso frustrating. I always wonder when mine will go south and what i'll do when it does... a lot will be lost but at the moment backing it up isn't exactly simple unless I find another drive for the Firewire case. Sometimes they go strange as well... I have a drive that will only start up if it's exactly at 0 degrees of tilt.