First, a simple test if you are not sure what kind of paint it is, then we show how to remove paint from plastic: both latex and oil. You probably have what you need at home already. Latex will become gooey when exposed to certain solvents. If latex, go to the post just about removing latex paint: you are the lucky ones. Is it still wet?
Depending on how long the latex paint has been in place and how large the stain is, you may have to try several removal methods before one finally dissolves it. But take heart: that stain soon will be a faded memory. Scrape off the excess latex paint with a blunt object, such as a spoon. Dampen a cloth or sponge with cool water and wipe the area to loosen the remaining stain.
Purchase a clay bar from a big-box store or online site. Clay bars are great for removing overspray from several surfaces. Some clay bar packs come with a spray, or you can use a simple auto body or glass cleaner, or even just soap and water. Can you please put wikiHow on the whitelist for your ad blocker?
If it's latex, I'd try just a good wash. If it's not latex I would see what the paint can label says about cleanup.