Scoop out a thin line of joint compound onto the edge of the spackle knife.
Place the knife at a 45-degree angle to the wall and push the compound into the seams. Continue pressing the compound into the seams until they are completely filled and the compound is flush or slightly higher than the wall.
Allow the compound to dry completely overnight.
Sand down the entire paneling with a circular sander and 80-grit sandpaper. Be sure to wear proper safety equipment including a mask, gloves and eye protection to avoid any dust irritation to your skin, eyes and lungs. Also, if possible, open any nearby windows for better ventilation to the room.
Wipe the entire wall down with dry cloth diapers to remove the sawdust. Continue wiping until the diapers come off clean when rubbed against the wall.
Paint over the entire wall with one coat of primer. Allow the primer to dry overnight, and the wall will be ready for painting in the morning.