There is T1 package which does repartitioning automatically - you do not have to digest all this information (useful but boring).
http://projects.mobileread.com/reade...upor-resize.7z
Just make sure that you have device with Sony's firmware 1.0.05... preferably in pristine condition

You will need SD card in the device, procedure is no different from normal rooting. If you want to speed it up - make sure that you moved all books OFF device