Basic question- how do I load multiple scripts?

So I'm making an electric long board controlled with a wii nunchuck, my only problem is my lack of arduino knowledge in general. Luckily for me, the code has already been made, however, I'm not completely sure how to load it. I've run simple arduino programs before but this one seems to be broken up into multiple parts, and although you can download the zip, will that work or just create a library? Thanks for your time guys!

Here's the github link

It should be as easy as extracting the zip and double clicking the ino file to open it in the IDE. All other files will automatically be opened in the IDE as well.

The rest of the process (verify / upload) is the same regardless if you have one file or a number of them.