Remixed top corner brackets that allow the use of the original hardware that came with the Lack table. You will need the bottom corner brackets and other parts from the source thing.
Place one of the cylindrical parts on the double ended screw from the Lack. Using pliers, screw the double ended screw into one of the legs with the cylinder against the top of the leg. Place the corner bracket over the screw on top of the leg. Screw the leg with corner bracket into the top piece of the Lack. The images show this sequence. Repeat for the other 4 legs paying attention to the location of the various brackets. All other assembly should be the same as the source thing.