The engine flush usually goes in with the oil before you drain it, so double check that on the bottle!
But otherwise, you're pretty much there. Run the engine so it's warm. Not full operating temp, but a decent temp. You don't want to burn your hands when it comes out the sump, but you don't want it so cold that it doesn't flow out. Let it drain as long as you can. Fit new sump plug and washer if it's there. Tight, but not over tight. Remove the old filter, doubt you'll be able to get it off with your hands, so I hope you have a tool for doing it? If not, you can pierce it with a screwdriver and lever it loose, but that's a horrible, awkward, messy job. It will still have oil in it, and oil will drain from the oil filter thread on the engine.
Fresh oil on the rubber seal on newfilter, and do it up hand tight. Don't go nuts with it, just nicely pinched tight. Some people put oil in the new filter too before fitting, I never have done though. Then fill her up and away you go
Oh, and wrong section
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