This is going to be and hard at the same time. First thing to do is get a Firewire External hard disk (as big as your current internal). Then backyup (Clone=bootable : Carbon Copy Cloner or Super Duper) and backup your current setup.
Then buy your new internal hard disk (like these) and get some tools (like this). Also foolow the site pictures at here and see the video right here.
Well is this enough?
__________________ PowerMac G5 Dual 1.8(Rev A.), , 7 Gig RAM, Pioneer DVR-110, ATI X800XT, OS X 10.4.11 & 10.5.4, 23'' HD LCD Mac Book Pro Core 2 Duo 2.16Mhz, SuperDrive, ATI X1600, 2GB RAM, OS X 10.5.4 Tibook 400Mhz, DVD drive, 1024 RAM, ATI Rage, OS X 10.4.7 1TB Time Capsule 5g iPod 30Gig White |