Insert the hex key into the clamping screw on the end of the Multi-Max. Turn the clamping screw counterclockwise, loosening it just enough to allow you to slide in the accessory.
Install the MM11 hook and loop pad accessory onto the tool's accessory holder, making sure all 12 pins on the holder engage the holes in the accessory. Place the accessory flush against the holder. Turn the clamping screw clockwise, tightening it onto the accessory holder.
Align the 60 grit diamond paper accessory to the hook and loop accessory, and use your hand to press the diamond paper onto the accessory. Plug the Multi-Max cord into an electrical outlet. Press the Multi-Max end with the diamond paper firmly against a hard surface. Briefly slide the on/off switch forward, turning the tool on, then slide the switch back into the off position.
Switch the variable speed control dial, located toward the bottom of the tool, to a setting between 6 and 10. Position the tool over the high spots on the concrete. Slide the on/off switch forward, turning on the tool.
Firmly grip the tool with both hands, and lower it onto the concrete. Use light pressure as you grind back and forth with a continuous motion. Allow the Multi-Max to do the work, and do not press down with extreme pressure. Grind the high spot down flush with the surrounding concrete.