Note: It seems that this youtube user's account got deleted.
Following his series, you can easily install a new OS on Android. He does Cyanogen 7 but I did 9. The only bad thing was that in How to Install Cyanogen 7, he makes a mistake of not putting the zip on the SD card before wiping everything. He uses a microSD card reader, which I didn't have but my phone was still able to connect to my computer, so it was ok. Otherwise, it's a very good instruction!
Google clobbers Cyanogen's modded builds. Interesting. This article has both good links to all the key points and articles and good commentary