About an hour, all told.
First I hit it with a base coat of khaki....(not going for heavy coverage).
Dry for five minutes each side.
Take a camo net (or rag with holes in it), and lay it on the surface.
Spray some brown, not hiting every hole, (just to keep it random).
Same holey rag for some green spots,
Then a light misting of khaki to blend and soften any sharp edges or spots.
Easy, peasy, lemon-squeezy.