do a search- a few threads on the topic.
you will need 1.6 litres of the correct oil, available from dreadnought, a 30mm socket, and to make the job a lot easier ( read possible), an oil changing syringe ( about £8 from machine mart).
it makes it a bit easier if you can jack the rear up a bit, and warm the car up first

Its a 15 minute job, if you are near lancs and can get to me you can use my socket and syringe