Disclaimer: There is an external callback called whenever templates are rebuilt which automatically removes branding for you when appropriate.

Installation

• Put the contents of the library directory into your XenForo library directory.
• Install the addon-dpSpy.xml file in your Admin Control Panel -> Install Add-on option.
• If you have a license for branding removal, you can enter your domain(s) here before you install to have branding automatically removed.

There isn't a whole lot to explain... you can see it running live here: https://forums.digitalpoint.com/spy/

Note: if you want the version that works with XF 1.0.x/1.1.x, download the 1.0.5 version.