I have a '65 Coronet 4door-into-2-door sedan conversion in progress, whith some AWB mixed in for good measure. Already had a fair donor; a '65 Coronet convertible that was a real gawd-awful mess and useless for anything other than a donor. I cut the quarters off, took the doors, and then found a 4door sedan later and started on it. It's all here: www.primerking.com
Most important thing to remember is this: if it isn't square/flat/level/straight when you start, it simply cannot be when you're done. Measure 3 times and brace everything before you start cutting and continously check everything in the process. You can't be too careful. If something gets crooked in the process, it'll be painfully obvious when you're done.