Hi.
For a rough DIY job You just:
1.Get some paint powder from a powdercoater.
2.Copy the curing times and temperatures from the box.
3.Clean the part.
4.Put the part into the oven, to a slightly lower temperature than the curing temp.
5.After about 15 min or so when the surface temperature is near to the set temp, take the part out from the oven and dust, sprinkle, throw, whatever You prefer, the powder to the surface of the part or roll the part in the powder.
6.Cure the plastic in the curing temperature.
7.If the paint thickness isn't satisfactory, repeat 5&6.
Do test the procedure before painting Your piece with a scrap piece of some kind.
It is really quite easy, but takes some practice to get an even surface and/or gloss.
While the curing can be performed in a conventional oven the results range from slight smell and taste in food to a loooong lockjaw & crosslegs and one hell of an argument

. (They do know what works.)
For a pro job, take it to a pro. Really.
Just my 0.02€
Sam