Drilling a granite countertop requires specific tools and techniques to avoid cracking or damaging the surface. Follow these steps to drill a hole in a granite countertop:

1. Choose a diamond-tipped drill bit that matches the size of the hole you need to make.

2. Mark the spot where you want to drill the hole with a piece of tape to prevent the drill bit from slipping.

3. Secure the countertop with clamps or heavy objects to prevent it from moving during the drilling process.

4. Place a small amount of water on the surface of the countertop near the drilling site to lubricate the drill bit and reduce heat.

5. Hold the drill perpendicular to the countertop and start drilling at a slow speed to create a small pilot hole.

6. Increase the drill speed gradually and apply moderate pressure to continue drilling through the granite.

7. Stop periodically to add more water and cool the drill bit.

8. Once the hole is drilled, use a polishing pad to smooth the edges of the hole.

To avoid damage to the granite countertop, it is best to hire a professional to drill holes or make any other modifications to the surface.