Welcome to the site. The solenoid replacement is a pretty straight forward ordeal. It would probably be a good idea to replace the transmission fluid and filter while you are changing out the solenoids. Make sure that the mechanic performing the repair has access to BMW Software so that the adaptations can be reset. If you contact Klaus at thectsc.com he can provide you with the correct solenoid kit for your vehicle and also any additional items needed to complete your repair. Good luck with your repair.