Step by Step tutorial for unlocking your device and cooking your own ROM!!!

[homoferus]

Hey guys. Couple months back I used this tutorial to flash my Sprint 6800 to Cricket with great success and ease. Thought I had done the same with my fiance's but must have had an ADHD moment and missed a step. Long and short is that I need to revert hers to original earliest SPL and Rom and then start over. I can't get the Cricket data services to work (just the internet). What do I need for this? Alternately, a link to a thread that describes how to revert it would work great. Thanks in advance.