full car backup and AC panel swap was discussed at the beginning. do that first, it's easy.
go on youtube and find a video to understand how to remove the level that opens the hood. you'll never figure it out by yourself but once you see (and you do it once), it's easy. then you need to gain physical access to the , it won't be very easy if you never did it before, and I don't really know how to detail it, try googling it, there might be videos on youtube. it's tight as hell, that is for sure.
1) disconnect the battery. if that was not clear, DISCONNECT THE BATTERY;
2) unplug the three connectors. they all have a lever that needs to go top to bottom, but it won't move before pushing a small latch. the center connector has to travel outside and then down in the white plastic rails;
3) can come out now, you need to swivel the bottom out of its holder, then comes down vertically. yes, it's tight.
CHECK IF YOU HAVE WIRES IN THESE POSITIONS: 1, 2, 5 of connector A and 40, 43, 56 of connector C.
4) basically reverse the procedure and put in the new . you are allowed to swear
5) re-connect the three plugs, do not swap A with C. I don't think the wires are long enough anyway.
6) connect battery. as soon as you switch the ignition on, will kick in.
7) set Long Coding of old to the new one.
8) dump admap of new and use WinMerge to compare to the old one. you need to manually set all adaptations to the old values, it will be A LOT, like hundreds. took me more than two hours. it's easier if you have a second computer with WinMerge, and another person that dictates you the adaptation and the value.
9) when you're finished, cycle ignition (wait a minute) and clear all errors. if you are left with errors only (in , and maybe other modules), you're good.
10) drive to dealer, have removed and keyfobs taught. bring them all.
if you don't have the wires in those six positions, you need to buy the loom and install it. that will be another PITA. do the modules first. do not put back all the dash trims you removed, especially DO NOT PUT BACK the hood level, leave it in the door pocket and use it on the fly if you need to open the hood.