in answer to your question, i use a nulon engine oil flush, i think its called 'engine oil flush' and its in a small black bottle.
there are other brands (wynns i think) that do the same thing and would have similar names
its easy, park the car where youre gonna change the oil, pour it into the oil filler, idle the engine for 10-15 mins, and then drop the oil out. just make sure its all really out as it thins the oil right out. and to NOT drive the car, for any reason, and dont rev it above idle. im sure you already know to change the oil when its still warm........