Custom IPSW for 5.0.1

[Ivel]

hey guys,

I'v been pretty inactive in the jailbreak community recently so I am not sure how to do this. Basically, I have an iPhone 4 that is unlocked with Ultrasnow. It's on Tmobile, and on version 4.0.2. I want to upgrade it to 5.0.1. I read that an untethered jailbreak came out for the A4 processors which is what I have I believe. How do I upgrade to 5.0.1 AND preserve my baseband? and then to jailbreak do I just use the redsnow? Thanks in advance
Edit: Or do I just use the new pwnage tool?

[Newbee123]

You need to download the lastest Redsn0w and the ios 5.0.1 stock filmware.
Run the redsn0w anh choose "Extras" then "Custom IPSW" it'll create the custom filmware 5.0.1 preserver baseband for you.
Then click on "Pwned DFU" and follow the instruction to put your iPhone into DFU mode. After it done, open iTune, the iTune will give you the message "....your phone need to restore....some thing like that...". Close that message and HOLD THE 'SHIFT' KEY ON YOUR KEY BOARD AND CLICK RESTORE (it's important if you don't hold the shift key apple will restore your phone with the current filmware and new baseband the you screw up). Then point to where you keep your custom filmware which redsn0w just created for you. After that it'll put the custom filmware and reserve baseband on your iPhone.

When it done, you use the redsn0w to jailbreak it. This time instead of choose "Extras" you click on "jailbreak" and follow the instruction to jailbreak your phone.

I just give you the general idea with my broken English. You can search for the clearly instruction around here or on youtube. Goodluck.

Edit: I'm using Windows not Mac.