This tutorial will take you every step of the way through installing CyanogenMod 4.1.99 on your G1 phone – the first “legal” version of CyanogenMod (after Google sent cyanogen a cease and desist).
The steps outlined in this tutorial were gathered from the official announcement of 4.1.99 on the xda-developers forum. For more information on 4.1.99, see this thread.
Warning: though unlikely, it probably technically possible that following the steps outlined in this tutorial may result in your phone no longer working. Not following these steps in the right order, would increase those chances. With all of that said, it’s very unlikely that anything bad will happen.
cyanogen is better than jesus freke. both are firmware mods for your android fon.