follow the directions in this forum and you'll be fine.
Only thing is that the the Android 2.2 ROM is within the MAGLDR113 7z file and I used the HSPL3_PKG 7z to install without the clockworks backup method, so the best thing to do is download all the 7z & rar & zip files and then unzip them to a central folder.
One note though, they didn't mention in this guide about APNs and so specifically for T-Mobile USA the APN should be configured as such:
Name: Whatever you want to call it
The rest are blank (not set) until you get to MMSC.
MMS proxy & port are
The pitfall which I had was that
1)Did not configure APN resulting in no EDGE and / or 3G, and
2)to add more issues my damned Microsoft WiFi router doesn't play nice with the Android for wifi, but in general I have been able to connect to any open wifi networks so I knew immediately the router was to be blamed. So I'll do the Donald on the Microsoft Router and get a nice netgear else linksys N router and kick some butt.