I had to cut one off on my LS just last week, it is easy to do, do not be too worried about it. Once most of the cut has been made, the chisel splits the alloy nut very easily. My nut had a bolt screwed into it to hold it onto the head, the PO was a country girl, I guess that is how you do it when you have to do something on your own. Now of course I find the threads totally nonexistant...she must have stripped it previously and the screw was just her way of continuing riding.
Get my frame back tomorrow morning after powder coating, then I can start the rebuild.