that is a #6 torx screw that holds that plate in place. you can go to sears and buy that #6 torx screw driver separately to. that is wehere I bought mine at. I see nothing wrong kriagster with the photo, course u stated u popled it backin. . On that side there is a lip that actualy goes under that grip that holds that side of the plate in place. If it doe sit again, I would call Kahr and get a new side plate cover, Might not have been properly ihn place in the first place and now that you popped it in,it should be OK. Tehre is zero pressure there.
by the way that is the same size #6 torx that holds the slide lock lever spring in place also.
removing that side plate does not allow any parts to fall out either, so fear not, That iswhy I have always said there is no reason to take that plate off... Kahr had to design it that way to get the parts actually in the lower section, unlike their steel versions which the grip area is skelotonized anyhow. the grips on the steel versions is actually the side cover...