How to use modified Ionic repository in an App?

I would like to change somethings in Ionic source code.
In more detail, I would like to hunt for the reason why multiple ion-toggles make the app slow to load (
Unfortunately, I could not find a guide how to use the modified source code in a test app.
Any ideas how to compile Ionic repository to usable package or directly import the modified code to my test app?

There appears to be a “link” script, so I would try running that in your forked version of the repo and then using npm link ionic-angular in your project to complete the link.