You could also try Numrich Arms on the Internet. www.e-gunparts.com
That is a manufactured stock, you would not need a gunsmith to just put another one on the gun. Unscrew the butt plate/recoil pad. There is a screw in the top and bottom of the back, phillips. The holes are hard to see in a recoil pad, but put some petroleum jelly on the screwdriver and just push it through. Once that is off, you will see a big screw head down deep in the stock. It will take a long, large screwdriver, probably 12" long. Unscrew it and the stock comes off. Reverse the procedure to put the new stock on.
You don't need to go to a gunsmith unless you want the stock fitted, but it is not fitted right now unless you had the work done.