Drywall sander - GIF

[hemmjo]

You can easily remove popcorn or a textured ceiling if it has not been painted. Water in a spray bottle. Spray it, wait a minute or two, scrape to off with a wide mud knife. You may need to do some touch up after to make the ceiling flat, but if you need to repair a textured or popcorn ceiling, it is easier to remove it all and start over, that it is to match. Or remove it all and go to a nice flat ceiling.

BUT if it has been painted or been sealed like Meyer77 mentioned it is a lot more difficult to remove.