Download iTunes
Download Tinyumberla http://cache.firmwareumbrella.com/downloads/tinyumbrella-5.01.00.exe
Download Sn0wbreeze http://hotfile.com/dl/125818066/1eeeede/sn0wbreeze-v2.7.3.zip.html
Download 4.3.3 Firmware http://appldnld.apple.com/iPhone4/041-1011.20110503.q7fGc/iPhone3,1_4.3.3_8J2_Restore.ipsw .