Changing an Epicor UserID

How impossible is it to change a userid?

For unknown and mysterious reasons, I was the one of two people in the entire company that were not assigned an Epicor user id that matches my Windows AD name. Using the FieldFinder query, I can see bread crumbs all over the system from my years of using the system. I would get brazen and just update the database using SQL, but I am afraid I will miss a column or two and get myself in a real mess.

Is there an Admin Tool for this? Or some other preferred method?