goto ibm's storage website
here
first, goto "verify warranty status and create RMA"... type in the S/N and P/N numbers from the drive itself. this will tell you if the drive is still under warranty. if it is, then you can create an RMA, and they will email you instructions on how to send it back to IBM (you pay shipping there, they pay shipping back)
i know this well because i had to send back 3 of these drives. i got really lucky this last time (about a month ago) as they sent me a 40GB 120gxp as my replacement
hope this helps