The quickest fix is to put a couple of toothpicks broken to length so that they just disappear, into the stripped screw hole. It's like putting expanding plugs into a hole in masonry, the screw will bite into the toothpicks and as they expand it will grab the side of the hole. A better fix is to fill the hole with some plastic and re-drill, then use the screw to make a new thread. When inserting screws into plastic always turn them backwards before driving them in. You will feel the screw pushing outward and then clicking in as the thread drops into its path - right after the click when the thread is in the right place that's where to start screwing in. Driving the screw in from any point eventually catches the existing thread and strips it, as someone found out with that Mac. These are a coarse-pitch thread so someone might have forced a screw in a few times!
There’s a two part compound called JB Weld that cures as solid plastic. It’s as hard as steel. You can fill the hole with it and wait for it to cure, then drill and tap it to rethread it and it should be as good as new.