can be a bit tricky but just follow instructions here:
http://wiki.maemo.org/Flasher


you can re-download PR 1.2 from :
http://tablets-dev.nokia.com/maemo-d...-downloads.php

do you know what firmware you using?
in my example my phone original came with UK firmware, but i changed mine to the worldwide firmware version instead as its updated more often then uk, i did not find any limitations by changing this but might brake the warranty, is up to you...


how to flash?
you need the cable that allows to plug into your computer.
follow the instructions in the link above to connect the phone and then from the CMD prompt just flash it with PR 1.2
fyi, i left out the vanilla part, and just had to re-install my apps, data was still there.