Pour a quart of 91% Isopropyl Alcohol (Walmart) in a large bowl or bucket then using 0000 steel wool or a fine scotch bite pad, holding the stock over the bowl, drench the steel wool in the alcohol and rub the stock with the grain, making sure to keep everything wet. THis will remove the old finish gently and there will be no need to sand the stock. If that is a stain, and you want to get rid of the stain you will need to be patient using the alcohol, it will eventually work most of the stain out.