on 3G, go to itunes, put phone into recovery mode by phone off, then press power button 2 sec, then also press home
button at same time for 8-10 secs, then phone shuts off, release power and hold home until itunes sees it. Hold shift down and click RESTORE
choose the right version firmware I used 3.12 even if phone was 3.13, then let itunes work. It will reboot to no OS, then run blackra1n and restart, then you can add cydia and blacksnow
restart again, should be unlocked.
d/l firmware version for your phone at blackra1n org /download/ to use with these steps