Open the tape. There should be five screws on the back - four on the corners and one in the middle.
Rip out the guts. Remove the tape reels, the metal piece in the center, and any loose pieces of plastic or metal. You can save the tape for future crafts. Remove the flap at the head of the case. Be careful not to lose the spring on the end.
Use pliers to rip off the plastic at the head of the case (where the flap is.) Be careful not to remove the piece where the corner screws go. Also rip out the V section at the bottom of the tape. You can use a small saw or a hot knife as well. Be careful of flying bits of plastic.
Glue construction paper or material to both halves of the VHS tape. You may want to trim the paper or material so it fits snugly. If you want to skip this step, just cover the holes.
Reassemble the case. Replace the flap and screw the case back together with the four corner screws. Now you can open the flap and put in anything you want to hide. If you have the outer case, put the VHS back in it for added security.