Remove all furniture from the room. Take down any ceiling light fixtures. Pull the floor molding off the wall using a small crowbar or hammer. Unscrew faceplates from outlets and light switches.
Turn off power to the room. Test that there is no electricity running to any outlets or light switches using a circuit tester. Lay a protective plastic sheet on the floor.
Roll strips of rosin paper along the floor over the protective covering. This will help absorb water and make clean up easier.
Use a spray bottle or garden hose sprayer attachment to moisten the ceiling. Work in small sections. Once a section is damp, use a wide putty knife to scrape the popcorn texture off the ceiling. Hold the putty knife at a 30-degree angle to avoid damaging the drywall underneath. Continue working in this method until the ceiling is stripped.
Dampen small sections of a wall the same way as the ceiling. Begin scraping off the texture from the top of the wall down.