Cutting the pelvic bone
I've started wonder why I even bother with removing it anymore though. My deer will be cut up either the night I shoot it or the next day and it will be kept cool, why mess with it? It's not like it's going to taint anything in that amount of time.
Cut around the butt whole like normal and then stick a corn cob up the butt. Then when you have the deer all openned up and about to remove the intenstine, grab the tissue with the corn cob in it and pull it inward to remove the butt whole.
My old college roommate from XX years ago told me that one and he even showed me a corn cob he carried in his pack, (light and free). He swore by it.
I haven't had the need to use one and I don't cut the pelvic either, but I never did forget that.
(It sounds even sicker as I prof read this)