Android Q

JesusFreke has found a way to register the G1 in the initial registration screen that comes up the first time you boot the phone (or after you wipe the phone). It will allow you to register if you don’t have a sim card at all, or if you have a sim card but no data [...]

Okay, for some reason you want to unroot your phone or bring it back to stock. This is useful if you no longer like custom ROM’s or need to send your phone in for warranty purposes.
This process will take you down to a stock firmware of RC29. If you just leave the phone on, you [...]

This is the absolute beginning to modding your Android phone. You will need to gain root access (rooting your phone). You will first downgrade to RC29 in order to make other changes. Once downgraded, you will install the test keys. You can then update to a modified ROM (with root access). Finally, install a modified [...]