Ryan, all of the moisture traps/filters I have ever purchased always had a valve at the bottom of the bowl. The smaller ones use a valve like you find in your tires. Just push it in and the moisture will be expelled. Just like letting the air out of your tires. The larger volume ones wlll have a valve with a tee handle that you need to turn to let the water out.
The bowels are clear, usually, so when you see water in them, just empty it.