Put the hammer on halfcock or remove it. Remove the ramrod. Remove the tang bolt. Use a pin punch or small nail with the end flattened to drive out the barrel pins. Lift out the barrel. Sometimes the barrel fits tightly into the stock and may need a few bumps with the heel of your hand to get it loose. The forestock is thin and fragile without the barrel in it so do not use too much force when removing the barrel. When you have the barrel out of the stock, put the stock in a safe place so it doesn't get broken. Be sure to put all of your removed parts (tang bolt and barrel pins) in a ziplock bag and put them in a safe place so they don't get lost. When you replace the barrel pins, fit them in carefully and tap them in place carefully so you don't mar your stock. If they don't go in with a few taps, your stock is not lined up properly with the holes in the barrel wedges. You may have to press down on your barrel to seat it back into the stock or use a rubber mallet to tap on your muzzle to get the barrel to seat. Patience and finesse is the answer, you don't want to force anything or muscle things back into place.