The 4E_JPG ruleset defines them in graphics.xml.Quote:
Originally Posted by dcook22
However I would create an extension as described above to overide the elements you want, in this case the GM token and the Portrait border icons. This way you don't have to edit the original ruleset files and unless the graphics change between releases you shouldn't have to worry about new releases of rulesets and having to reedit the files each time.