Upgrade a Jailbroken/Unlocked GSM iPhone 4 from iOS 5.0.1 to 6.0.1?

[greyhounds]

Disclaimer: I have no clue what I'm talking about.

I think it might be possible for me to upgrade my phone from iOS 5.01. to iOS 6.0.1.

Here are its current specs:
- It is a GSM (AT&T) iPhone 4 (Model MC536LL)
- AT&T authorized me to unlock it via iTunes, but I unlocked it using redsn0w's "deactivate" feature instead.
- It is jailbroken already (using redsn0w), and running iOS 5.0.1
- When I open Cydia, it tells me that I have the following "SHSH: iOS 5.0.1, 5.1, 5.1.1, 5.1.1r1, 6.0.1"
- It currently has modem firmware 04.11.08.
- I upgraded my computer to iTunes 11 yesterday.

So here's how I think I can upgrade and remain untethered and unlocked. Am I understanding this correctly? I'm drawing from multiple sources.

- Open redsn0w 0.9.15b3
- Extras > Even more > Restore
- Download IPSW "iPhone3,1_6.0.1_10A523_Restore.ipsw" from iClarified - iPhone - Where To Download iPhone Firmware Files From
- Tell redsnOw that it's OK to upgrade my modem firmware (???¿¿¿) Is my unlock "official," even if I used redsnOw to do it?
- click "remote" to tell redsn0w to use the SHSH blobs that are on Cydia. How does redsn0w know which blobs to use? There are saved blobs there from 5 different iOS's.

And then redsn0w will "stitch" my blobs on Cydia into the IPSW... and my phone will have a jailbroken iOS 6... and still be unlocked??? Or will I screw everything up if I do the above?

Thank you so much for your help!

[Simon]

Your unlock is official so you don't have to preserve your baseband.
The jailbreak on 6.0.1 is tethered though. Nothing you do with redsnow will change that.

[greyhounds]

Oh.
I understand now. I read on the dev team blog that the new redsnow allowed untethered hactivation on 6.0. I thought hactivation was a way to jailbreak.

I get it now. Thanks