There are several options for painting and it all depends on how much work you want to put into it.
The simple and easiest way is to clean the panels sand them (this allows the paint to ahdear better). I use a high grain sand paper around 600 grit to 900 grit and you just want to sand lightly so the panel are no longer smooth and shiny. Then you want o clean this very well with a degreaser. Some options I’ve used with success are simple green and soft scrub. After this you then spray paint the panels. Krylon acrylic is a good choice but there are many options. Use as many coats as necessary to have a uniform color but as few as possible but at least 2. Let this cure for about 3 days. If you can put it in direct sunlight for a few hours a day as this will help cure the paint. Paint may be dry but still not cured so 3 days is a good estimate. After that you want to put on a GOOD clear coat. There are lots of clear coat options and they vary in how you use them. This is by far one of the best I have used but once you activate it the can is only good for 48 hours ( http://www.ebay.com/itm/111298452665?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT ).
The other option is to use an airbrush or spray gun. It takes more coats as they are super thin but you get a much more even coverage. Also with airbrushing you are less likely to get paint runs, blistering, wrinkling and other issues common with spray paint. The process is the same [ sand, clean, paint multiple coats, cure time, clear coat].
Another more advanced complex option that I have not personally used is electroplating of plastics. This is expensive and time consuming but if done right will produce far superior results. It’s probably far beyond what you want to do but it is an option.