First, check for asbestos! After that, use a sprayer to put water on the popcorn, it will soften. I taped a 6” scraper to the end of my wet/dry vac hose. Throw down a drop cloth, get to spraying and scraping. You can do that from a ladder if needed. Then run on the wet/dry and get to scraping. The vacuum sucks most of it up easing the cleanup. Then after it is all clean and dry, sand/patch any spots that need it.