Cutting off the barrel and recrowning the muzzle is not too tough—if you've got the right tools. Come with me as we shorten the barrel and recrown the muzzle on an old Winchester .22.
For this process, we'll need a Wheeler Engineering dovetail-cutting fixture. First, clamp the fixture on the barrel at the desired length. A standard hacksaw with a fine-toothed blade will cut off the barrel in short order, using the Wheeler fixture as a guide.

Now, true up the muzzle with a smooth file. The hardened fixture will help get the muzzle square with the bore. We'll need a little cutting oil, I'm using an 11-degree reamer, and a large tap handle. Do not try to hurry this.

Once the reamer work is complete, remove the chatter marks with some abrasive paper and thumb power. The finished crown should be completely smooth.

Well, it all starts with a hacksaw and ends with abrasive paper and your thumb.
-- Larry Potterfield