Before any disassembly, locate the hot and cold water shutoff valves under the kitchen sink. Turn the handles clockwise until they are fully closed. Then, go back to the faucet and move the handle to the 'on' position in the middle to release any remaining water and pressure in the lines. Place an old towel in the sink basin to catch any water drips and to protect the sink surface. Gather all your tools and the new faucet repair kit.

Locate the small set screw that holds the handle in place. It's typically hidden under a small decorative cap on the side or back of the handle base. You may need to pry this cap off with a small flathead screwdriver. Insert the correct size Allen wrench into the set screw and turn it counter-clockwise to loosen it. You usually don't need to remove the screw completely. Once loose, lift the handle straight up and off the faucet body.

With the handle removed, you will see a chrome dome-shaped cap. Unscrew this cap by turning it counter-clockwise. It should be hand-tight, but if it's stuck, wrap a rag around it and use adjustable pliers to get a better grip and avoid scratching the finish. Once the cap is off, lift out the plastic cam and the rubber cam seal beneath it. Note their orientation for reassembly.

Simply lift the ball valve straight out of the faucet body. It has a slot that aligns with a pin inside the faucet body. Next, look inside the body to see two small rubber seats, each with a spring underneath. Use a small flathead screwdriver or needle-nose pliers to carefully pry out the old seats and springs. Insert the new springs from your repair kit into the holes (wide end down), followed by the new rubber seats on top of them.

Since the leak was identified at the base of the spout, the O-rings must be replaced. Lift and twist the entire spout to remove it from the faucet body. You will see two or more rubber O-rings around the base. Use a small pick or flathead screwdriver to carefully remove the old O-rings without scratching the metal grooves. Clean the grooves with a rag. Lightly coat the new O-rings from the repair kit with plumber's grease and slide them into place. Re-install the spout onto the faucet body.

Reassemble the faucet in the reverse order of disassembly. Place the new ball valve into the socket, ensuring the slot on the ball aligns with the pin in the faucet body. Place the new rubber cam seal and the plastic cam over the ball, aligning the tab on the cam with the notch on the faucet body. Screw the dome cap back on and tighten it by hand, giving it a final quarter-turn with the pliers (using a rag) if necessary, but do not overtighten. Finally, place the handle back on and tighten the set screw with the Allen wrench.

With the faucet fully reassembled, you can now test your work. Slowly turn both the hot and cold water shutoff valves counter-clockwise to restore the water supply. Check for any immediate leaks under the sink around the supply lines and valves. Then, turn the faucet handle on and move it around to test both hot and cold water flow. Carefully inspect for leaks around the base of the spout and from under the handle. If everything is dry, the repair is complete.