Just copy the .dll file to (note the Xamarin Studio version, it might be different today): on Windows : %LocalAppData%\XamarinStudio-5.0\LocalInstall\Addins on Mac : /Users/[YourUser]/Library/Application Support/XamarinStudio-5.0/LocalInstall/Addins Source: http://forums.xamarin.com/discussion/comment/6356/#Comment_6356