well i think you could use a load of different hacks to get to the latest CFW. Tiff, GTA, Lumines. Tiff is probaly best as you dont need a game for it, just an image. You then need to downgrade to 1.5 so you can then upgrade to the latest CFW.
Check here: http://pspupdates.qj.net/QJ-How-To-3.../49/aid/129133
You'll need to upgrade to 2.80 by the looks of it. Read the 2.80 section, where there is a link to the update. Hope that helps.
Bookmarks