First step was to widen the barrel channel, which I did with a set of scrapers I purchased many years ago, when I was fitting custom stocks to airguns I used in Field Target competition. That was the easy part. The trickier part was going to be filling the magazine well and finding some sort of escutcheon to retain the screw that holds the action in place.
I sawed and planed a filler strip of rosewood, as I had a strip of 1/8" stock on hand. This was glued in place and scraped to level it with the stock. The escutcheon was turned from a threaded brass insert, using my drill press and a dangerous looking setup involving holding a lathe tool in a vise. It was then epoxied in place, and the wood filler strip was stained black with a Sharpie, and finished with MiniWax Wipe-On Poly, as the stock is poly finished.
I didn't want to shorten the screw used with the original stock, in case I wanted to use that stock again, so I cut an M5 screw to length and turned down the head to fit in the escutcheon. I then blued it using Brownell's Oxpho-blue and dipped it in Brownell's Water Displacing Oil.
Last step was to shape the bulky, symmetrical, cheek piece to fit my head. This was done initially with a belt sander, and then with a random orbit sander, a scraper, and finally hand sanding with 320 grit paper. Boyds gives you plenty of material to work with; I probably could have started with a saw.