Maybe when you have time you could write up the How TO........ Please
1. Warm engine up a little, turn off.
2. undo sump plug and drain oil.
3. remove oil filter
4. leave to drain for a bit to get as much old oil out.
5. fit new oil filter, smear clean oil on the rubber seal before tightening by hand, not too tight.
6. refit sump plug
7. Fill oil to correct level, don't overfill.
8. start engine and warm oil a little, check for leaks.
9. leave to settle and check engine oil, top up oil to correct level again if necessary
10. shut bonnet and enjoy a beer
I take no responsibility for how you use this information and if you screw it up and wreck your car, that your fault
Don't forget to put oil back in before your start your engine
Don't forget the part about refitting the filter and sump plug before filling again
Personally I wouldn't bother with putting flushing fluids in your engine, just use a good quality oil and replace every 7000 miles.