It most likely isn't made by Grizzly, just sold by them. Is it by chance a Kedu HY56? This is a switch with the big paddle stop sold by many companies. I just bought one today from Busy Bee here to install on my router table when I get it built. All you have to do is attach the hot (black) feed wire to one side terminal (any one), and the line out black to the plug for the router on the opposite side. Any set of terminals will work. If it was 220V, you would switch both hot wires, and if 3 phase all three hot wires.
The neutral (white) wire can get spiced with a wire nut in the box. The ground should be spliced in the box, and grounded to the box as well.