Ive done the retrofit..but then again I've done way too many changes to my car..
For ICM upgrade there is a thread you can follow :
https://www.drive2.com/l/578467636975763496/
AND
https://www.bimmerfest.com/threads/n...mw-f10.849376/
ICM retrofit may require modifying ducts under center console IF you have 4 zone AC.