Root Unroot g1 1.6

[ozster12]

So a couple of days ago i got a G1 from my bro that he bought off craigslist and i want to know how i can unroot it or even root it just so the tmobile sim will work on it. Everytime i try putting in my sim it asks for a network sim unlock pin and tmobile says my Phone is rooted because of the Build Number Which is DRC92. I was wondering how i can unroot or even root just so i can actually use my phone service. I have tried the following instructions at least 10 times. Im Currently on Fw 1.6

How To: UnRoot Your T-Mobile G1/Get Back to Donut | TheUnlockr

Unroot - android-roms - How To: Remove Root / Stock G1. - Project Hosting on Google Code

If someone could please help me i would greatly appreciate it.