Ok, I ran into that explanation after you declared it was found using Google.
I get the idea they are using a Varibit which is a cone bit on the tip. Do the same with a piece of extra stud stock, but in reverse. (make it a cone shape like the bit -- in male form). Weld it to the broken stud. The rest is pretty vague, but I would then thread two nuts on there and use the nut's internal thread as the drill's max OD.
The nuts will help guide the drill bit into the center of the new stud. Assuming all of this is lined up right. When drilled out you should be able to unscrew the double nut of the welded on stud and remove it. Doubt you can do all of this with this small of a size ...
I had a run at this about a year ago.
My opinion is that the bolts were cast into the aluminum.
I bought some threaded rod stock, a regular tap and a bottoming tap in hopes that I could get any of them out. Uh, no, not on my first attempt.
Most of the processes used to extract studs/bolts from aluminum were not counting on the extremely small size of these.