This is the guide to manually uninstall xcodes and alternative xcodes
Source :- https://stackoverflow.com/a/53575585/10422074
For a complete removal of Xcode 10 delete the following:
/Applications/Xcode.app
~/Library/Caches/com.apple.dt.Xcode
~/Library/Developer
~/Library/MobileDevice
~/Library/Preferences/com.apple.dt.Xcode.plist
/Library/Preferences/com.apple.dt.Xcode.plist
/System/Library/Receipts/com.apple.pkg.XcodeExtensionSupport.bom
/System/Library/Receipts/com.apple.pkg.XcodeExtensionSupport.plist
/System/Library/Receipts/com.apple.pkg.XcodeSystemResources.bom
/System/Library/Receipts/com.apple.pkg.XcodeSystemResources.plist
but if you don't want to lose all of your customizations, consider saving these files or folders before deleting anything:
~/Library/Developer/Xcode/UserData/CodeSnippets
~/Library/Developer/Xcode/UserData/FontAndColorThemes
~/Library/Developer/Xcode/UserData/KeyBindings
~/Library/Developer/Xcode/Templates
~/Library/Preferences/com.apple.dt.Xcode.plist
~/Library/MobileDevice/Provisioning Profiles