Those 6 cds are the recovery disks, once you have installed the new hard drive, all you should have to do is put disk one in the cd/dvd drive and restart the computer.
here is some more information about the HP restore process:http://h10025.www1.hp.com/ewfrf/wc/documen...168&lang=en
when you use the hp recovery disks, they are supposed to place the computer in the factory original state. You will have to do some cleanup for trial applications that you dont need or want, and update to service pack2 and run windows update. you should not require activation or a product key, in some rare cases you will have to call microsoft, just use the key on the OEM sticker on the side or back of the computer.