I remember seeing an online video of someone upgrading the HD in their P2000. I would suggest using google or searching youtube.com for a video. I do believe that they installed the HD in an external enclosure and copied it before trading it out.
FWIW, here is one video
http://video.google.com/videoplay?docid=-3637613075261606641but I guess the OP knows about them, else he wouldn't have attempted the upgrade.
Note: all P2000 firmwares I know of have a 128GB limit on partition size. Doesn't prevent you from using a suitably partitionned bigger drive though. Anyway, the P2000 is severely outdated and one can find netbooks that do a decent job as storage devices, and a bit more, for less than the price of the latest "Pxxxx" generation.