So I have the head and I want to end up with just a skull and horns.

Just skin the head, take out eyes, brain, etc. de-bone it and boil it?

Is that the easiest way?

The easiest way but also the smelliest way is to put it in a bucket of water after skinning, if its cold put an aqurium heater in there too, and leave for 10 days or 2 weeks. When you can pull it out and spray with the water hose and all the goo falls off then empty water put it back in with clean water and dawn dish soap for another week or so, this will degrease it, after that pull out let dry and whiten.

The last one I did I let the maggots eat the brain out. It made the boiling part pretty easy. Of course you need some mild weather and place to keep it where nothing else can get to it. The garage floor by the door worked well for me. After I boiled it I cut up some old socks, or you can use gauze, soaked the socks in Sally Beauty Supply 40 strength peroxide. I then wrapped the skull with the saturated socks for a day. I bought a mounting board at Hobby Lobby and stained and poly'd it. Total cost - about $6. Definitely wear some rubber gloves when working with the peroxide.

I've tried two ways, wrapping the antlers with foil:
1) hanging behind the garage under some cover for about 2-3 months
2) more efficient but exposes it to the elements - digging the head into the flower bed with foiled horns above ground. leave it for about 1-2 months and it's usually completely cleaned out.

Boil and bleach/peroxide.
take foil off and enjoy

my brother sticks them in an ant bed for a couple weeks and then bleaches them when they are cleaned out. His look just like the pros do. We do hog skulls the same way.

I skinn the head, remove lower jaw, and eyes. boil in water till meat and stuff comes out. If you want it to look white, put a couple bottles of peroxide in with water and boil it a little longer.

I skin the head pull the eyeballs out and lower jaw off and clean everything else off I can with a knife. Then I put it in boiling water for a few hours with some about a 1/2 cup of 20 mule team borax(laundry soap). After boiling it for a while pull it out and remove the rest of the meat. Usually most of it will just fall of but for the stuff that doesn't a small wire brush will do the trick. Be sure not to get the base of the horns to wet while boiling them so they don't get stained. After your done tape up the base of the horns real good and soak it in a tub of bleach over night and you should be done