Install
- Download the .dmg and open it;
- Drag Sogou Input Method into Applications;
- Confirm the input method installation and authorise with your password.
Enable and switch
- System Settings → Keyboard → Input Sources, tick Sogou;
- Use Ctrl+Space or Caps Lock to switch input sources;
- Customise the switch key under Sogou Settings → Keys.
Uninstall
Remove it from the input source list, then delete the app from Applications. Export your personal dictionary first if you want to keep it.