You can uninstall IBM® Lotus® Notes® by dragging Notes.app from /Applications to the trash. This preserves user data.

You can also uninstall Notes using the uninstaller application supplied with the Notes install media. This preserves user data as well.

You can also uninstall Notes by dragging the following items to the Apple® Mac OS X® trash bin:

  • Notes.app
  • ~/Library/Application Support/Lotus Notes Data folder (“~” = user’s home directory)
  • ~/Library/Preferences/Notes Preferences
  • /Library/Receipts/Lotus Notes Installer.pkg
  • /Library/Receipts/Lotus Notes Installer_English.pkg
  • /Library/Receipts/xpdcoreinstaller.pkg

via IBM How to uninstall Notes client from the Macintosh – United States.