Hey there, as @Craig Walker said, just apply where you need water to break up the product and go. I used a q-tip and my fingers to really get in there; chin and I suppose where you would define his "cheek bones" at. I also spread a bit through the forehead.
I can't speak for others, but Chewie was shedding while I did this. I used a small comb with a lot of teeth, but I had one good furball at the end once I had went through and broke up some of the product matted fur throughout the body. So just make sure to not be overzealous, especially on the face. Practice a bit on the body so you have a feel for what you're doing.
I don't know how much experience you have with hair, but a general rule for detangling is to begin at the bottom and work towards to root - slow, short motions, hold the fur near the root to keep it from yanking and pulling out as you move upwards. Like I said, practice a bit with the body so you know the feel. Work with your fingers to loosen product on the delicate areas on the face before you take the comb to it. Just dab/rub water on those spots until it begins to loosen.
BE PATIENT. Go a little bit at a time, wet thoroughly where needed. Note that it's a good idea to keep a few fresh paper towels to slightly dry out the areas as you work so you can assess your progress faster. Lastly, make sure he's completely dry before you put him in your shelf, if it's a relatively enclosed unit (i.e. detolf) You don't want to trap moisture!
I'll be honest, short of ripping hair out, there's not much you can do here that will make him look worse than he is out of the box. Any mod you make will improve it - but combing the chin out, "fluffing" his features, making smooth hair lines through the forehead, and isolating his moustache are areas I would focus on. Other good things are to loosen the forearm hair, and get the matting out of his thighs. The shoulders on mine had a particular amount of product, breaking that up helped smooth the transition from the "beard" to the body.
Here's the final result of an hour and some change worth of work. I don't even feel the need to add color, the blending and lightening seemed to happen as I combed out all the fur across the body.
