Does anyone know how simple changing the battery in my Focus' key is, and if simple, does anyone know the type of battery I need to buy? The battery in the remote 'Siemens' key must be about 5 year's old now, and has very little transmitting power to operate the remote central locking. I've not had a car with remote central locking before, so don't know if I'm best off changing the battery myself, or getting the garage to do it.
Any advice appreciated.
Chris