Searched and Cannot find help with Jailbreaking, Plese HELP

OK, I have looked on here and all over the internet.

I am not a complete Noob, but if you give me precise directions I will follow them.

I just bought an iPhone 4 from my friend, it was on version 4.02 (which i Know cannot be Jailbroken) with Baseband 1.59.00.

He reset all content and settings and took his sim out, there for the phone itself is stuck on the connect to iTunes screen.

Now, I know that 4.1 can be JB using greenpois0n or Limera1n, however I want to unlock it so want to keep the 1.59.00 baseband.

I found something called "tinyUmbrella" which apparently updates your iPhone 4 to 4.1 without updating the baseband.

I did everything right except when I went to itunes it said their is no sim card in the iPhone you are trying to activate, please insert simcard.
So i cannot, restore the iPhone as it says in the instructions.

should I try and downgrade to IOS 4.01? will this keep my current baseband?

I know NOT to update.

Could someone please give me a link or be kind enough to get my iPhone working, (or Hacktivated) on any 4.0 OS.
It does not have to be 4.1, as long as I can use it without it getting stuck on the connect to itunes screen i will be good.
As long as someone can help me keep the 1.59.00 baseband that will let me unlock, I am happy.

Unfortunetly, my friend, like I is from Chicago, but I bought the iPhone from him this weekend, and i go to school in Bloomington, IN. None of my friends here have the iPhone 4, So I cannot borrow a sim card to try the tiny umbrella method.

I have a windows 7 laptop btw, and can use a friends MAC.

What is the best thing to do??

*EDIT*
Just found out my friend has an iPhone 4, if I were to downgrade to 4.01 successfully, and put his sim in my iPhone 4 when it is off, and turn it back on, will I have to connect to iTunes to activate it, or can I simply go to Jailbreakme.com and JB my iPhone, and then give him his Sim back??