Unless you have a torch and a lonnnnng pair of needle nose pliers, your otions are limited (heat them and bend them 180*). Take out one screw and use a drill bit the same size and drill the head off the other screw. Avoid over drilling and metal chips, use an extension magnet to get the old screw and nut out. Then you´ll probably have to use a sheet metal screw on one side. Why are you removing the cap anyway?