I'm definitely going to leave something out, as i do it without really thinking these days and it's much essier to demonstrate than explain but here's a rough description.
1. Insert the blade under the skin at the base of the skull and work down the dorsal stripe. For a shoulder mount it's safest to work at least 6" past the shoulder/crease. For a pedestal i go two thirds down the belly. Just allows for your mistakes and taxi mistakes.
2. From the end of the cut, cut around the sides and meet on the belly side.
3. Work the skin toward the legs.
4. If you haven't had experience with caping its easiest to "sock" the leg. Basically at the elbow joint of each leg cut all around. Then slowly skin your way down on the inside of the leg. Once you make it down to the cut on the elbow you can push the hock through.
5. Keep working until you've made it to the end of the neck/start of the jaw top and bottom.
6. With the skin rolled forward toward the head so you dont damage it rock the head back and forward. You'll notice the pivot point at the base of the skull where it meets the neck. If you drive your blade through that central part you'll go straight through and sever the spinal cord. From here cut all the way around getting all the meat, sinew, oesophagus etc. Cut. At this point twist the head around once or twice and itll break. After that should be good.
If you want to face cape its a little finnicky. I work my blade up from the base of the dorsal cut to a few inches before the antler/horn then Y off to each antler/horn. Once there work around with either a screw driver or knife to pry away the skin.
At this point start working down the face. When you get to the eyes and pre orbital gland be very careful and take your time.
Keep working down and it's easiest to just take everything of the nose with some cartilage.
You will need to turn the ears and split the lips but if you're getting it to your taxidermist within a day they'll be fine. Neither is hard but is tedious.
Main thing is to be careful on the neck, armpits and face as it's very thin skin and easy to cut through.
I'd reiterate being careful around the eyes and pre orbital glands. Just take your time. Ideally use a scalpel or a fine sharp blade.
Except for the cut around the elbow for socking always cut from the inside of the skin, cutting from the outside cuts the hairs and it gets everywhere on your meat.
Ask me any questions you have for clarification or for more info. It's one of those things that's easy to leave detail out without thinking to include it.