Both Night and my mod are "open". As open as anything in Xbmc, my mod is under Creative Commons Attribution-Noncommercial-Share Alike 3.0 License, that means...
You are free:
* to Share — to copy, distribute and transmit the work
* to Remix — to adapt the work
Under the following conditions:
* Attribution — You must attribute the work in the manner specified by the author or licensor (but not in any way that suggests that they endorse you or your use of the work).
* Noncommercial — You may not use this work for commercial purposes.
* Share Alike — If you alter, transform, or build upon this work, you may distribute the resulting work only under the same or similar license to this one.
http://creativecommons.org/licenses/by-nc-sa/3.0/
You can´t open the XbT files, there is no decompression program or method for it. In order to have access to the media tree folder and files you need to download from the GiT, same as with any other skin. The only way is download threw GiT. You can see how to install GiT in the first post were I explain what you need.
Hope I helped, ENJOY!!