When finished printing, the hinges of the lid does have some tension to it, just bend the hinge until you hear a snap and the hinges feel free because there are little plastic dots used as supports on the inside. It might feel like you're going to break it but don't worry, you won't.
There are two size screws that print with the container. The slightly smaller screws screw in to the back with the lid while the longer screws screw into the front to be used for the hinges.
There are three separators with different sizes. There is the center divider made to slide into the center, then there are two almost identical with one being slightly wider than the other. The slightly wider one is made to slide in with the center divider while the less wider one is to slide into the top and bottom compartments.