On the sump, there is a 17mm stop. Take it out and drain it into a bucket or something like a bottle. (not in the suwer please). Bring it to a place where they take it in.
Than take of the oilfilter which is located behind the radiator.
Put on a new oilfilter(7 quid at the dealer) but the bolt back into the sump and fill the oil on the top of the engine with 4.5 L of 5w40 Castrol Edge TD.