Hello. Fuldraw' s link to the Outdoor Life site that depicts the boning out process is the best I' ve seen. We use this technique almost exclusively and it cuts down your work significantly. One variation if you' re not keeping the hide is to simply make the initial cut along the top of the neck down the top of the back to the rump then follow the same series of steps as shown in the link. All of us pack a hundred feet of parachute cord in our packs to help secure the game bags in trees etc.
Insure you use elk/moose bags that are much thicker than standard deer game bags. A couple years ago I had to use some deer bags and they just were too thin resulting in having to throw a large exposed front shoulder over my shoulder for the last mile out - wasn' t fun!
Use of a tool known as the Wyoming Knife is a great aid as well. These knives are normally in Cabela' s or similar pubs. Regards.