Equip the grinder with a medium-grit diamond grinding disc.
Mist the slate floor with water.
Set the concrete disc in the rear position. Start the machine. Lower the concrete disc until it spins against the floor.
Move the grinder in a slow side-to-side motion while taking it across the room in successive rows.
Turn off and unplug the grinder. Switch the grinding disc for a slightly higher grit and go over the floor once more.
Continue switching to higher grits and going over the floor. Finish the floor with a fine-grit disc.