Get a variable speed grinder, a backing pad, a felt wheel and some Diaglo polishing compound. Here are the links:
http://www.defusco.com/bosch-variable-speed-angle-grinder-p-2515.htmlhttp://www.defusco.com/flexible-backing-pad-velcro-p-1939.htmlhttp://www.defusco.com/alpha-felt-wheel-velcro-back-p-2360.htmlhttp://www.defusco.com/glues-epoxy-polyester-etc-stone-polish-c-82_508.htmlI didn't specify which Diaglo because you didn't tell me if it was light or dark granite.
The first thing I would do is treat the spots with an alkaline solution to make sure all the acid is sucked out of the stone. You can use either caustic soda and water solution, or if it is a small area and you have Drano, use that. Drano is a great alkaline solution, I don't recommend it for large areas as it is a lot more expensive than the caustic soda. Put the solution on your stone and lay a paper towel over it to keep it moist for 30-60 minutes, then clean the stone thoroughly with water.
Now put the felt wheel onto the backing pad and screw the backing pad onto the grinder. Turn the RPM down to position 1 or 2. Sprinkle some of the polishing powder over the areas you need to repolish. Mist over with water. Use the felt wheel to turn the powder/mist into a paste. Buff paste over the area (similar to buffing a car) until you have the desired result. Remember to keep the paste a little moist. You may have to do this process more than once to get the desired results. It depends on how high a polish your slab has and how much the stone was etched.
Glad to be of service,
Mark
