Select (or Apps > Special App Access on newer versions). Find the option for Unknown Sources .
for a particular Vodafone TV Box model, or are you looking for software-based sideloading instructions? Vodafone Tv Box Unlock
If a box is locked due to a forgotten PIN or system error, a factory reset can be performed via Settings > Device Preferences > About > Factory Data Reset Third-Party Launchers: Select (or Apps > Special App Access on newer versions)