Nice one thats cool for me, 1 more question though, i know i wouldnt do it to my own iphone or ipad but what would happen if he updated his phone to higher ios than 5.1.1 by mistake when available ? What are the consequencies.
If he does that, he will lose his jailbreak. If the version he restores to (he won't be able to update, only restore. You can't update a jb device), cannot yet be jailbroken, he may be stuck with a stock device for a while, or since it is an iPhone4, he can choose to downgrade it to 5.1.1 using saved SHSH Blobs. Cydia will initiate saving his blobs automatically the first time it is started. If he uses an app like PkgBackup when he is jailbroken, he can save away his JB apps, tweaks and settings as a backup to be restored in the future should he make such a mistake!
Rather than getting you to do it, it sounds like he should get himself over here and read a few threads himself! Better to know what you are getting yourself into than rely on a mate to do it for you! No offence to you of course! If he isn't able to work out how to jailbreak, I don't really see the point of him doing it... He won't get much value from enhancing his device without getting to know the capabilities, and doing the jailbreak itself is a great first step. Unless of course that's not the reason for jailbreaking, in which case, no more help from us!