Hi, if you're wanting to upgrade (reflash) your tablet from a linux computer then the instructions are all on the maemo.org wiki:
http://maemo.org/community/wiki/howt...magewithlinux/

Just use the 2008 .bin file instead of the 2007 one listed there, the link to download it is also on the wiki, although it sounds like their servers are getting hit pretty hard right now.