w580i - Unlock? - Need assistance

Ladies and Gentleman...

I need assistance with unlocking a AT&T phone (Sony Ericsson w580i). I would like to use it with my T-Mobile account, which has a smartchip. I have the USB cable for the sony phone.

I don't exactly know how to start doing this and need assistance. I'm computer-literate so I'm capable, I just need to know the steps, where I find the files, and what I need to do.

I'd like to preferably do this for free or a minimal amount of money, since times are tight right now.

Thanks in advance for any info you can provide.

General Information about Patch-Unlocking (start here if you want to unlock) - Top Sony Forums

Hi friend i was also thinking of unlocking my friend's sony phone and i found the unlock code by logging onto Unlock-Free.com : Unlock your mobile phone for free
and that was really useful.............