Need urgent help regarding my iPhone 3G 3.1.3!

[Grapesipod]

Ok, so I had a jailbreaking and T-Mobile unlocked iPhone 3G running 3.0. I wanted the 3.1.3 update so I updated my iPhone 3G to 3.1.3 via Shift+Restore. So it turns out, my baseband got updated to 5.12.01 and my bootloader is 6.2 (I don't know if thats relevant) and I'm stuck with the emergency screen. Apparently, I can jailbreak+unlock the iPhone with 4.0 easily following these instructions:

"Update through iTunes (official update)
Download redsn0w 0.9.5 b5-5
Download an IPSW
Run redsn0w
Install ultrasn0w

The fix for the slow 4.0 on 3G is to disable background image and multitasking (you will be prompted to enable/disable this when your run redsn0w)"

This sounds like its easy to do, except, how do I get out of the emergency mode to update to 4.0? I need to know how to bypass the emergency mode and be able to do it. Can someone help please? This is urgent.

[kwine]

Put the phone in DFU mode then itunes will prompt for restore.