Well I needed to recode a door lock for the passenger & drivers side of the Dart so I took some pics and am doing a mini write up.
I started by taking the old lock top off and removing the springs. Next VERY CAREFULLY tap the top pins out in order. Do Not mix these up. After the top pins are out the bottom pins come out ALSO IN ORDER, lay these in order on a clean work surface. Take the lock to be recoded and do the same. REMEMBER THE TOP AND BOTTOM PINS CORRESPOND. I needed two locks to get the right sized pins so you may have to have a second one as a spare.
Now take the pins that you took out of the donor locks and carefully match them to the pins that are in order out of the lock that you are keying the new one too. THESE NEED TO MATCH EXACTLY.
Once I had the pins matched exactly, be careful some may look close but are not the same, I put back together my original. Take the bottom pin and place it in the bore then tap it down gently. (remember point first) Once all the bottom pins are in insert the key and make sure it rotates. Now carefully do the same with the top pins and springs. If the lock is hard to turn STOP it should be as easy as butter. Don't force anything to rotate. Don't forget the top.
I like to crimp the top again then put a piece of electrical tape around it to ensure it stays tight.
Now do the same with the lock you are re keying. Take your time and remember the pins look similar but are slightly different so if the key is sticky you may need to change out the incorrect pin for the proper one.
I don't know if someone wants to tech archive this but feel free to do so.