flushing radiator coolant in RV 100/ SYM joyride 200?

not sure if I need to remove the radiator but was thinking:

1-release the water pump cover on the right side and let the old coolant drain that way.
2-then close it, put half the amount of radiator flush liquid (its made for cars and my radiator holds only about 1.5 total)
http://www.amazon.com/dp/B0002KL6I8
3-fill it with water (should it be distilled water or regular water is fine?)
4-let it run for 10 minutes
5-reopen the water pump cover and let it drain. close it.
6-fill with water a 2nd time and let it run for a few minutes and drain a 2nd time, or I should I just fill the radiator with water (with water pump cover open) till it comes out clean?
7-close the WP cover and refill with antifreeze

the scooter in question
http://www.bikez.com/pictures/sym/2008/28109_0_1_2_joyride 200_Image credits - Sym.jpg

thank you for your help.

I meant RV200 not 100