Download the MetalKettle Repo and save to a location you can easily find later
Open Kodi / XBMC
Select SYSTEM
Select Add-Ons
Select Install from zip file
Navigate to where you downloaded the zip in the first step and select repository.metalkettle-1.4.3.zip
Wait for Add-On Enabled Notification
Select Get Add-Ons
Select MetalKettles Addon Repository
Select Video Add-Ons
Select Erotik (XXX)
Select Install
Wait for Add-On Enabled Notification
The add-on is now installed and ready to use
As usual the add-on now can be accessed via VIDEOS > Add-Ons from your home screen.