its pretty easy mate any one can do it.
1. warm the car up just till you can touch the sump pan with your hand and its warm.
2. turn the engine off and leave for 5 mins for the warm oil to settle to the sump.
3. remove the sump plug using the square sump plug tool from most motorfactors for about 3.99 use a bowl to drain in with a capacity of atleast 4 ltrs.
4. remove filter with hands or use a filter removal tool if its tight.
5. spread some fresh oil on the new filters rubber gasket to help fitting and stop seizing when changing filter next time and tighten up with hands not a tool !!!!!!!!
6. once all oil has drained refit the sump plug if magnetic sort then clean magnet and re-fit.
7. fill with the correct amount of oil and leave to settle between filling and check on dip stick DO NOT OVER FILL!!!! overfilling is just as bad as no oil.
8. warm oil up to correct tempriture and turn off engine and stand back and tell yourself good job man cup of tea time.
and for the price of a filter ''under a fiver''

its not worth leaving a old one as a clean engine is a happy engine.