it's pretty easy, issy:
http://www.slatedroid.com/index.php?topic=7942.0
I am not adept and had no problems.
The various custom firmwares are all supposed to be pretty good. They're probably you're best bet to start with (nchntrman's is pretty much all-in-one and the least buggy)
I chose to update to the November official pandigital firmware (because of reports that the reader works better in it) and I added the alternate homescreen patch, the volume key patch, and the "change the SDK to 8" patch so I could add Adobe X pdf reader.
I use mine exclusively as an ereader and it works great. The built in reader works very well for ePubs and officially released PDF books. Adobe X handles scanned pdfs like a champ.
Good luck and congrats on a great buy.
(I'm so happy that back in Sept I planned to get a K3 for 140 bucks, but it's worked out that I got both an eink reader and a little tablet/PDF reader for less than that price combined!)