Buttstock: One visible screw on top of tang, one under the receiver cover and spring guide.
Pistol Grip: One screw from underneath.
Upper handguard: With bolt carrier removed, rotate the lever on the right side of the rear sight housing up until you can lift the upper handguard / tube assembly out of its notch. Grip the rear of the gas tube assembly in a vice and then grab the wood with your hand. Rotate it 180 degrees and pull 'down' away from tube assembly. Careful not to marr the wood. That metal keeper in the wood just pulls out of the bottom.
Lower handguard: Lever on right side of gun (looking down the barrel) rotates up with a screwdriver. Once it's rotated up, you can tap the front ferrule off with a plastic tool such as the handle of a screwdriver. Tap the ferrule forward and then slide the wood forward and down.
Good luck!