So you stripped the little screw. I can think of two fairly simple fixes.
Using a dremel, grind a centered line into the stripped phillips threads on the screwhead. Make it so you can simply remove it with a larger flat head screwdriver. Once the screw is removed, all you have to do is find a new screw.
Let's say that doesn't work. Let's say the EZ Out method doesn't work. Simply make an accurate measurement in another part of the clutch drum so that you can drill and tap for another screw of the same size.