hahaha... making a mountain out of molehill is half the fun of these projects!

Don't sweat it, you'll find out it's no big deal. Keep in mind that before there were metal wrenches for sale we were using a piece of PVC and cut the fingers out to fit the grooves in the barrel nut. It worked. So... that will give you an idea of how little effort is required to remove and replace the barrel nut. Here's a How-to link for those who might be interested. Smith & Wesson M&P15-22 - 5