I'm just in an extra hostile mood today.
So start here:
http://forum.ppcgeeks.com/showthread.php?t=27071
Download BuildOS and the build19213 files.
Hold the pwr button, record button, and hit reset to put the phone in bootloader mode. Write down what version your bootloader is, then hit reset.
Fire up BuildOS and select the LennySH build 19213.
Select your bootloader version.
Select your carier.
Hit the play button to build/flash the ROM.
If it all works, then go through BuildOS and start adding some options/programs you want. If you get a white screen after a flash, you put too much sh*t in the ROM. Remove some stuff and try again.
Remember, you won't brick an Apache with software. God knows I tried.