reformatting t40 please help

[dangit]

how can i reformat a t40? i've searched already on this site and it didn't help. i did not get any CDs when i purchased my thinkpad. i have heard that to reformat i can do it from the hard drive itself since that's where the software is located. how do i go about doing this or is it better to request a formating CD from ibm? thanks in advance.