erasing and re installing tiger onto powermac g5 to sell/give away

I have a powermac g5 which I'd like to sell or give away. I've followed the instructions to erase & re install tiger onto the hard drive from here; how to restore my Powermac to its original settings

That worked really well ... apart from I'm now stuck on "Registration information". So, the erase & installation of Tiger was successful to this point. I obviously don't want to put my information in here as I'm going to sell it (or do I?!) There doesn't seem to be anyway to bypass this?

Please help!

Regards,

Paula.