google and 'tube works, but you can also just print the official instructions from the site lol
http://uk.playstation.com/ps3/support/network/detail/item250047/Use-the-data-transfer-utility/
the reason to delete everything but saves is for time consideration - if you're not worried about time, don't worry to delete. check the site for snags you might encounter with trophies, LBP levels and Home stuff
and yeah - you'll have to match firmware versions

Proud Sony Rear Admiral







