If you have to ask how to compile it them you shouldn't be messing with it. There is no reason to bother with it unless you are a developer putting it into a app.
It literally says right in the repository how to build it
Building
Just run make with devkitpro and ctrulib installed. This is a normal homebrew application that is meant to be launched as a 3dsx.
I want to try fasthax but i can not find the 3dsx file Where I can download it
I know it's alpha
Good Luck and Happy New "Brick" Year
That's kind of ridiculous. It's not possible to brick with this file, as it doesn't do anything right now except escalate permissions, and then turn itself off.