as above do i need to change anything else when doing a barrell change..cheers

no but you do have to code the new barrel to the bcm " switch on ignition smart lock will flash & beep ,just leave it on untill the smart lock goes off & beeps about 25 minute then start the car all done

if your only replacing the barrel, and not the whole assembly you dont need to do anything..

if your replacing the whole assembly eg complete with ignition switch wires ect, you will need to train the bcm to accept the ignition switch...