1.根目录下的必须要用管理员权限：

sudo rm -rf /Applications/Xcode.app 
sudo rm -rf /Library/Preferences/com.apple.dt.Xcode.plist 

2.然后删除自己目录下的：

rm -rf ~/Library/Preferences/com.apple.dt.Xcode.plist 
rm -rf ~/Library/Caches/com.apple.dt.Xcode 
rm -rf ~/Library/Application\ Support/Xcode 

3.以及和开发者相关的：

rm -rf ~/Library/Developer/Xcode 
rm -rf ~/Library/Developer/CoreSimulator 
rm -rf ~/Library/Developer/XCPGDevices

xcode缓存目录

~/Library/Developer/Xcode/DerivedData