Hey skrik!
Its not too hard
If you download the newest JassNewGen pack and start the WE, there should be a box in one of the dropdowns called UMSWE. Just make sure its turned on
Once on, restart the program and there should be some extra fields in the "Game Interface" window at the bottom
A few of them are for fonts
Just import the font you want to use, then type the path for it into the text boxes
hope this helps!