Use a spray bottle filled with water, and spray the ceiling, moistening completely. Take a wide blade putty knife or joint compound knife, and round the corners of the knife (grinder will work) so they don't dig into the ceiling. The "popcorn" application should scrape right off. Messy job. Be sure to have plenty of plastic covering your floor. Repeat until free of the application. You'll need to prime your ceiling before painting. All considered, a day's work & a savings of about $5990!