Hi, Ya fancy lad! Core, you say huh? It's a plugin, so you install it like any other plugin, and it really depends on the contents of the archive. For all I know, there could be another archive inside of it like matryoshka doll.
Download DevTools from poggit and extract the contents of your zip file into new folder inside plugins folder.
So yeah, "Core" is basically multiple features unrelated to each other packed inside of a single plugin. Installation is the same as any other plugins!