Assuming that your paneling is in repairable condition, there’s no need to tear it out. Preparation is the key to success in painting over paneling. As long as you can repair any defects and create a surface to which paint will adhere, there should be no problem. Here’s how.
Start by cleaning the paneling to remove dust and dirt. For grease, use a commercial cleaning preparation. Fill any nail holes with spackling compound, let dry, and sand. Sand all paneling surfaces with 100-grit sandpaper just enough to roughen the surface. Then sand the trim and caulk any cracks. Prime the paneling with a latex stain-blocking primer followed by two coats of latex wall paint.