Gday Gregorbian
To paint 5 o'clock shadow all you have to do is get an old old brush that youreally don't want anymore and cut most of teh bristles of it till you only have about 1/2cm left on it.
This is going to be your whisker brush for now on, now get the paint you want to use and lightly dip the brush into the paint and and wipe away any paint onto a piece of paper in a back and fourth motion till it looks like that there is no paint left .
With the brush ever so lightly go over the facial area with the brush till you start to see the paint coming off you might have to do this a few times till you get the desired affect doing it this way will let you choose how light or dark you want the facial hair.
this is what it should look like if you want a lighter facial hair.
Ron