RMRK.net SMF Theme, 7th Edition
To install on an SMF forum, you must create a .zip of the theme's root files. The .zip that github gives you (https://github.com/Roph/rmrk7/archive/master.zip) creates an additional sub-folder.
Note what whatever you name the .zip will reflect the theme's directory in your SMF installation.
You MUST follow the modification instructions in modifications.txt. This will not break any compatibility with any other SMF mods of themes, but will enable extra variables and features used by this theme. Without making these modifications you will encounter errors (these errors will become silent errors or fall back to stock behaviour in the future)
After initial install, simply upload or copy over any newer revisions, overwriting your current rmrk7 theme to update.