THE PREVIOUS OWNER OF MY HOUSE REMOVED WALL PAPER AND FAILED TO REMOVE THE GLUE BEFORE PAINTING OVER WITH A GLOSSY PAINT. NEEDLESS TO SAY, THE WALLS LOOK TERRIBLY LUMPY. IS THE BEST WAY TO REMOVE THIS TO JUST SAND IT DOWN. WILL I EVEN BE ABLE TO SAND THROUGH THE PAINT OR IS IT BEST TO JUST REDRYWALL THE ENTIRE BATHROOM?
You will have to judge whether the effort is greater for repair, or replacement. To repair this wall, start by using a scraper to knock down any high spots, follow with light sanding (power palm sander) just to take off gloss. I would skim-coat and sand the entire wall flat, then repaint. New drywall is an option, but bath fixtures often make the job more difficult.