Someone didn't put the lint trap in correctly, now

Someone didn't put the lint trap in correctly, now the place where the trap goes (the trap holder), has a lot of lint in it. Can't vacuum it all out. Tried to remove the trap holder, but cannot. How do I do it? I removed the 2 square head screws that I thought held it, but only the top right side of the holder will move a little. I'm afraid that there is a tab or something I need to release, I fear that I will break it if I push too hard.