you need the special red plastic primer for tha paint to hang onto the flexing plastic. Bumper can stay on, but mask off the rest of the car. Bumpstrip will need to be removed.
1st, clean and sand down with coarse wet&dry. Clean again. Primer, 3 coats & 15 mins inbetween to dry. When done, wet&dry the primered surface till smooth, with fine (2600) wet&dry. Make sure not to rub it all off though. Spray colour paint on top, i did 3-4 coats so its well thick and shiney. again, wet&dry surface (dont worry about it, it will shine up with laquer). Then laquer on top (after 24 hours to dry colour paint) i also did 4 -5 thin coats. When dry, use something like autoglym poilish, or some sort of super polish stuff, and rub hard till it shines.
JOB DONE