Pretty good advice. Gut her, bone her out, or at least quarter her out. The butcher can make do with the pieces you bring in. You don't need to lug the head, legs, and ribs to name a few pieces. Make gravity work less on you and you'll get her out OK.
Take a hatchet to use with your knife. Use the hatchet like a hammer to drive your knife through the pelvis, the rib cage, leg bones, and neck bones.
Leaving the pieces with little to no value behind makes sense if the climb against gravity and natural obstacles is otherwise overwhelming.