Hey there, painting/refinishing is what I do for a living, so I thought I could help! You will definitely need to strip that first (don't bother to sand that..it would be a huge pain in the ass). Make sure you are in a well ventilated area when you do it, and wear chemical gloves (stripper burns!) Apply a heavy coat of the stripper on a 2' x 2' square with a 3" or 4" chip brush (since they are cheap and disposable). Once you get a thick coat on a section, place wax paper face down on the stripper, making sure that the stripper is touching the wax paper. Apply stripper to the next section, and cover it with wax paper as well. Continue until the entire surface to be stripped is covered. When the first section has been sitting for about 15 minutes, remove the wax paper and use a plastic putty knife to scrape away the finish. Repeat on the rest of the sections. Apply more stripper to areas where the finish was not entirely removed. It sometimes takes a couple of coats before you get a clean surface. When you have gotten everything you can get off with the stripper, take a piece of fine steel wool and some mineral spirits and scrub the surface lightly. This will help remove any finish that is stuck in the wood grain. When you are finished, take a rag and some mineral spirits and wipe the surface down. You will then have a surface ready to stain!

If you need any advice on staining, let me know!