Before disconnecting the old battery take note that the radio code may be lost also if the car has central locking make sure the keys are in your pocket. The battery cables are secured with large round plastic terminals which unscrew anti-clockwise. If they won't undo by hand, carefully use pliers or molegrips. The battery is held in place by a metal bracket secured with one bolt.
Once the new battery is fitted turn on the ignition and wait 1 minute before starting, this allows the engine management system to reset.
Dann, September 2007