Just follow a basic compiling tutorial. Instead of using Haxe 4.1.5, use the latest Haxe, the issues mentioned in the guide are already fixed.
Just edit the source code it's not that hard (unless you can't code)...
For the non-coding people, you can mod the characters and add your own, since the positions are not hardcoded anymore.
Psst... Don't tell anyone, but i'm working on making an official version of the engine that is 99% moddable. -Erizur