I used Jasco Premium Paint Remover. I let the paint remover stay on for about 15 minutes then I used a heavy green scrubbing pad that is designed to remove paint etc with paint remover. Go with the grain when rubbing. If you have a couple of sections that are stubborn, add more remover, wait a few minutes and start rubbing again. Clean the holes with a Qtip and remove the masking tape from the inside. After everything is removed, wipe the drum down with a paper towel.
Note: I put some masking tape on the inside of the drum to cover the holes so the paint remover does not leak into the inner ply.
After all the paint/stain was removed, I used 220 grit sand paper on an electric block sander and gently finished removing the remainder of the stain. I finished the job with 600 grit followed up with 000 (super fine) steel wool. Wipe the drum down again well, and if you have access to and air compressor, blow the drum down to remove any remaining sanding dust.
Note: The outer ply on some drums are VERY thin (like the thickness of a dime) make sure you don't over work the drum and burn through the ply.
Remask the holes from the inside and apply the stain or paint of your choice following the manufactureres directions..go slow and hop easy.
Note: I use old tshirt pieces to apply stain instead of a brush.
Hope this helps...I will be more than happy to answer other questions..I'm sure other people can add to this as well.
Cya,
Mike