Sweep the floor to remove all dirt and debris.
Set up your steam cleaner according to manufacturer instructions, usually by filling up the water tank (often with hot water) and then attaching the tank back on the steamer. You do not need to add any cleaner.
Use an attachment with an opening about 4 to 6 inches long and an inch wide, if possible.
Turn the steamer on, and go over one row of tile. As you go, wipe up any residue with a clean wet rag. Continue up and down each row, until your floor is complete, rinsing the rag with clean water as necessary.
Attach the wand tool with the smallest opening so that the steam that comes out is concentrated.
Go back over the grout (make sure it's in good condition and not crumbling) with the wand tool, holding it about 1 to 2 inches away. Go slowly, letting the steam and water clean the fine grout lines. Wipe away the wet residue as you go with the rag. Continue to rinse the rag in clean water as necessary.