If you use the action wrench or a barrel vice it's very easy 90% of the time. 5% of the time requires add'l leverage on the nut wrench (easy to do, they come with a spot to attach a heavy socket wrench to it) or a 3-4 pound hammer. The other 5% requires heat penetrating oil and all of the above. It's not that big a deal, its just frustrating because it should never be that hard.
However, when removing the smooth barrel nuts... THAT's A TUFFY. Now you need a large Vice grip or pipe wrench or something like that and the action wrench. Or just cut it 70% through in a couple places and ream on it with your wrench. It'll break free. Once you've removed a smooth nut, you'll never want to replace it with another like it. They are the second stupidest things Savage ever did to mess up a good thing. (the other was moving the top bolt release to the bottom.)