Empty the base cabinets to prevent dust and the potential of something dropping on breakable dishes.
Turn off water and unhook all plumbing and appliances.
For any type of countertop, first remove the 4-inch surround if you have a separate one. Cut any caulk that attaches it to the wall and to the countertop with a box cutter or caulk knife. Use a pry bar to gently pry away from the wall.
To remove laminate countertops, plastic, or sometimes molded surface countertops, check for brackets and screws underneath. These are usually in the corners. Stone or granite are rarely screwed. For all countertop types, there is often a caulk line between the cabinets and the countertop. Check both the inside and the outside of the base cabinets. To remove, use a utility knife, and cut the caulk line, being careful not to mar the cabinet faces.
After all caulk is cut enough (both inside and out) to release the top, gently lift the countertops from the front to a 30-degree angle and pull out from the cabinets.