ok, here it goes:
1) uninstall your current itunes.
2) reinstall 7.5 (you can download it here
Old Version of iTunes Download)
3) download firmware 1.1.4 ( download here:
IPhone Firmware Download Links - ModMyI - Wiki)
4) connect Iphone, place in dfu mode (turn off phone, hold power + home for 10 sec., let go of power button while continuing to hold home for 10+ seconds), then itunes should recognize it. Also, when your in dfu mode your screen should be completely blank, but itunes should recognize your phone.
5) In itunes on your iphone properties page, shift click "restore" and find the firmware you just downloaded.
6) Wait for restore.
I highly recommend that you upgrade to the firmware that you wish to pwn before you actually pwn it. I had more problems trying jump from 1.1.4 to a custom 2.0.1. Could just be my phone. Hope you get it duder.
Edit: oh yea, when you upgrade your itunes back to a current version (which you need to do in order to upgrade to 2.x.x firmware) keep the 7.5 installer file around, it might come in handy.