All theme’s must be put on the hub in the “.wd_tv / theme” folder. Dump the new theme folder in their.
Make sure you have “show hidden folders and files” turned on for your OS or you wont see the .wd_tv folder.
Then go to setting on the hub and you will see appearance and themes. Then choose your theme and apply.
There is nothing to set up on a theme, once you apply it… it just works if compatible with your firmware.