Typical through-bolt; you'll need a long screwdriver with the end ground to fit.
Depending on how old (rusty) it is, a loooong soak in penetrating oil (Kroil) might be necessary to remove the stock without buggering up the screw. Some heat and vibration will help, too. Patience is the key: some of these old guns take weeks to months (literally!) of soaking with penetrating oils to free up rusted screws.
Removing the forend is simply a matter of pulling the front of it down.