I'm pretty good with tools, but I wouldn't do the barrel shortening myself. There are plenty of guys on the forum that could and would do it, but not me. I'd find a good gunsmith. Surely that won't cost too much to have done.
But, maybe you could just cut off one inch and see how it goes. If it goes well, then go for the full reduction. Worst case, if you botch that first test cut, the rifle will be out of action only long enough to find the gunsmith.