"Other space" and clean install

[debudebu]

I've got 4 gigs of "other" space taking up room on my Ipad. I'd like to do a fresh install and see if some of that is deleted.

I'm on 4.2.1 Jailbreak and I'd like to go back to that again, what's the best method to do this? thanks

 

[debudebu]

bump
I don't need a step by step, but I'm curious when I reinstall from backup will Itunes force the new OS on me? thanks

 

[scirica]

Since you are jailbroken, hopefully you've been saving your SHSH blobs along the way. If you have the 4.2.1 blob you can restore to that firmware and then do your jailbreak, get your apps back from iTunes, etc.