Make your first cut around the body of the deer 3-4 inches behind the shoulders, Make your 2nd and 3rd cuts around the front legs at the knee, carry both of these cuts up the backside of the legs to the armpits and then back into the first cut around the deer's body. At this point you should not cut the skin anymore, you should be able to skin the deer down to where the head and neck meets and saw the head off. Take to the taxidermist ASAP. Ideally you should already have a taxidermist in mind that you want to use and have talked to him about the hours you can bring the head by to drop off.
Good luck, I hope you catch a biggun'!!

Mark in SC