Uninstall Xcode on macOS Sierra
While title says this is for macOS Sierra, this should work for any version. And we assume that you are familiar with basic Mac functionality and using Terminal or the command line. Let's get cleaning!
Delete legacy Xcode installs
If you started with an old version of Xcode, this may need to be done first. If you get a "not found" error, don't worry and skip to the next step.
sudo /Developer/Library/uninstall-devtools --mode=all
Drag-n-drop Xcode into the trash can. Then empty the trash. You know how to do this.
Delete Xcode 💩
Even after being trashed, Xcode turds still lurk. Delete them.
sudo rm -rf ~/Library/Developer/ sudo rm -rf ~/Library/Caches/com.apple.dt.Xcode
Really old installs might have one more step:
sudo rm -rf /Library/Developer/CommandLineTools
Double check that the command line tools are also uninstalled. Open up Terminal and type
make. If everything worked, an annoying dialog will pop up saying how it couldn't find Xcode.
Bonus: Rebuild Spotlight and AppStore indexes
Unfortunately, Spotlight and AppStore still thinks Xcode is installed. In time, they might correct themselves but it's easy to make them do the right thing.
In System Preferences, under Spotlight, under Privacy, add the main hard disk. Typically it's named
Macintosh HD and if you don't see it, you may have to enable it using Finder preferences. Once you've added it, wait a few minutes and the entire Spotlight index should be destroyed. You can test by typing anything into Spotlight and the results should be very boring.
Then remove the privacy setting and reboot. The computer's CPU will run hot for a while since it is reindexing everything.
Finally go into the AppStore and search for Xcode. It should say it's not installed and give you the option to download.