Okay here is the very very easy way, load up curse launcher make a new profile call it Obscurity leave the default 174 etc, hit back at top left, right click the new Obscurity Icon & open file location, add all the files from the zip into the new instance Obscurity, of course you add from the zipped minecraft folder into the instance minecraft folder, hit play & let it build, little under 2 minutes later it will be loaded & ready to play.
You can do the same with vanilla by loading minecraft & making a new profile loading it, then quit & drag all the files from zip into it & reloading.
edit:
Had a quick look, it seems to work fine its gonna be hard to grow a couple of trees with no way to make a protecting wall or fence.
Looks good, I am just too tired to try it out now.