While the skin is still soft, cut all of the skin away from the antlers
Thats the best thing to do if you want to preserve the horns natural color. If you leave it hanging up outside, the horns will get sun bleached. Cut the skin away from the skull cap and antlers. Then clean any meat or "brain gook" away from the skull cap. After all thats done you can put salt on the cap to dry it out. A little clear varnish on the antlers to keep the natural color and you should be ready for the mounting kit.