How can I soften and reshape the horn of a bull?

Sometimes soaking in white vinegar will soften things like eggshells if you don`t wait too long. The horn will get harder as time goes on so hurry. 

Youtube has videos of people boiling horn and then *carefully* clamping in a vise to reshape.

You can't I don't think

I have made a couple Powder Horns from antlers .... I KNOW it is morning,  I just wanted to get y'all wound up. In view of others calling Antlers  horns, I thought I would do the same in reverse and see how they like it.

I use a nice piece of flat wood, and cut and shape to to fit and close the large end. Take a "nip" off the pointy end till you have the hollow. Now I make a wooden plug to stick in that hole. Use Leather shoelaces as the shoulder hanger and to tie the plug to the horn so it does not get lost in the furry of the hunt.

"Keep your powder dry" young whippersnapper.

Here is one I made long ago. The image is clickable, BUT I think if you save it, use your photo viewer you can enlarge the image to see detail.

I'm afraid not. They will stay the same shape.