would like to downgrade from 4.0 and unlock phone- need help!

[alpalontherun]

I upgraded my iphone 3g to 4.0 and its ******. I am about to send my phone overseas to my dad and would like to downgrade to the last version of software and then unlock it for my dad to use overseas. can you help?

 

[Applejuiced]

You can JB and unlock a 3G model on 4.0 also.
http://www.iclarified.com/entry/index.php?enid=10188