iPhone 3GS Downgrading from iOS 6 to iOS 5.1.1

How to downgrade your iPhone 3GS from iOS 6 to iOS 5.1.1
Programs you'll need:
Redsn0w: https://sites.google.com/a/iphone-dev.com/files/home/redsn0w_win_0.9.14b2.zip?attredirects=0&d=1
TinyUmbrella: http://cache.firmwareumbrella.com/downloads/tinyumbrella-6.00.01.exe
iTunes (Version 10.6.3): http://support.apple.com/kb/DL1427
5.1.1 .IPSW: http://osxdaily.com/2012/05/07/ios-5-1-1-download-links/
Warnings: You must have had your phone jailbroken previously, and have SHSH blobs saved on Cydia for this to work. This is a tutorial, and has worked for me, but if anything happens to your phone I am not responsible for it. Following this tutorial could brick your phone if done incorrectly, so use caution.
Stitching a custom IPSW:
Step 1: Download and install all required programs/files Step 2: Plug in your iPhone Step 3: Open up TinyUmbrella Step 4: With your device on and plugged in, click Save all SHSHs Step 5: Put your phone into DFU mode

1. Power down your device by holding the sleep button until slide to power off appears, and slide it.
2. With the phone off, hold the power button and the home button until the apple dissapears, then let go of the Sleep button and hold the power button.
3. You will hear a sound on your computer and iTunes will pop up, saying the phone is in recovery mode
4. Set phone aside.

Step 6:

1. Open redsn0w.exe
2. click extras
3. click SHSH blobs
4. click Stitch
5. click IPSW
6. find the IPSW you downloaded
7. click local
8. browse to C:\Users\(name here)\.shsh
9. select the 5.1.1 IPSW
10. let it do its thing
11. the file it created will have a bunch of numbers infront of it, and will be located in the same place as the IPSW file

And now you have a custom IPSW with your SHSH blob.

Installing the custom IPSW:

Step 1:

Go back to TinyUmbrella and click Start TSS Server

Step 2:

Reopen iTunes

Step 3:

Right click restore 

Step 4:

locate the custom IPSW file you created previously

Step 5:

Let it run its course

Once it's finished, you should have iOS 5.1.1 installed on your device! From then on you can jailbreak it again and do whatever you like.

It took me 3 days to figure this out, going through multiple versions of redsn0w, iTunes, and everything else with no luck.

Thanks to all the jailbreak developers, Apple, and everyone else for coming up with what I used.