hope i've posted in correct place i'm looking for an idiots guide to replacing the CIM in an Astra H aka mk5 using op-com software. due to my horn has stopped working and it now adjust my stereo i've been to Vauxhall and they say its already had the repair done in 2011 so they wont touch it even though its suffering from the same issue they recalled it for. i've already had the CIM out and when I replace the air part the horn works and it works after the airbag is replaced until I turn the engine off and then it goes back to how it was controlling the stereo. anyone that can give me a guide how to use op-com for replacing the CIM or even have any ideas about anything I can do with the CIM which may make it work again will be gratefully received.