RE: Changing stock on 870
you should just have to remove the recoil pad, with a screwdriver, and then use a socket with a extension to remove the nut on the thru bolt holding the stock on. YOu can find stocks from just about any store. Cabela's, Bass Pro Shops, Midwayusa.com, 870's are very common so you should have no trouble finding exactly what you want for a stock