My friend who is not very tech savy asked me to fix his 4GB unlocked on 1.02. He unknowingly updated his phone over iTunes to 1.1.3. and now needs me to fix it.

Anyone can link me to a site? I checked hackthatphone.com but I couldn't find anything specific to this situation. I know the baseband needs to be fixed due to the anysim 1.0. I just need a step by step guide to follow, preferabbly a site like hackthatiphone would be good.

Any help please?

you are on the site already, just SEARCH
plenty of information here
When you search, couple things you need to know:
1. Your phone is 3.9 BL
2. You need to virginize
I'd suggest start with "downgrade 1.1.3" then "virginize how to" "3.9 virginize", then go to "unlock 3.9"