How to work with headlamps and HCMs in OrBit (flashing, config, used HCM install)

[Marky mark]

Hi all I'm new here and find myself in a similar position to Svoi83. I've purchased a XC60 with the left headlight missing following an accident. I've sourced a replacement used headlight and fitted a new controller. My options seem to be either get the headlight software or purchased a used controller and recode. I read somewhere the headlight software needs to match is this correct? Any guidance would be greatly appreciated. 

TIA