As you probably know, Predam Iphone means unlocked Iphone.
The community “iPhone Dev Team" has just published a method relatively simple and free to unlock the iPhone which is called iUnlock. You'll be able to use your Iphone on any network, iUnlock is a 100% software solution. It is therefore not necessary to open the iPhone and leave his post to lean.
Read the article if you need to recover your Iphone Data