I had the same problem when I first got mine. Lift the top of the shell and carefully move it side to side and eventually they will start to release. Be patient though, Capcom didn’t really design these cases to be opened often and the plastics are getting more fragile as they get older. You can also try and lift the top shell and take a thin flathead screwdriver and carefully push the clips in to release the top shell. Most of these clips are already broken off on most boards. Once you get the top shell off, I would take some fine grit sandpaper and file down the edge on the black clip. It’s better to just file it down a bit rather than to risk damaging the colored shell from taking it on and off.
Hope this helps!