Push up on the lip of the black cap.(right side in pic) See pics
The set includes: (6) 6TPI 6 inch blades (2) 6TPI 9 inch blades (5) 18TPI 6 inch blades (2) 14TPI 8 inch blades (1) 10TPI 9 inch blade
The end that is black will open easily if you push up on the end that has a small tab on it. The opposite end has a hinge.