How to fix leaking/malfunctioning cutouts?

I have a Mustang with cutouts and for a while they wouldn't close all the way unless I hit the button. Now the left one works completely fine while the right doesn't seal all the way closed and never opens up at all. I don't care if I have to permanantly keep them shut or whatever I just want the sound of an exhaust with no leaks. Any thoughtout answers would be helpful. Thanks!