I'm also starting to use LED.
You can only modify the maps created with LED, if you have the file with .MP format. Those who have created the maps have those files.
To the question of modifying the Fugitive maps, Master Prospero could respond better than me. As you can see, these maps are so big, complex, (years of hard work), that modifying them with LED would be a "almost impossible" if you do not know how it was created step by step ... and that only the author knows.
I would only dare to modify the Phyton code, to adapt and correct improvements ... Sorry, I did not want to sound too sad, but to start with LED, I say humbly, better start working with smaller and simple maps, not start with impressive masterpieces ... That's for later of some years of study.