There are single handle and double handle sinks. Most newer Delta kitchen sinks are single handled ball valves. The single handle ball valve operates both hot and cold water. This ball on a stick device opens and closes a passage way that lets hot or cold water flow. Push the handle to the right and you have hot water and to the left is cold.
Turn off the water at the shut off valve underneath the kitchen sink.
Use a 1/8 Allen Wrench to remove the set screw that holds the handle in place.
Slide the handle off and set it aside. This now exposes the stick ball assembly. The stick is surrounded by a white plastic material which is the top of the domed faucet housing.
Remove the Chrome domed housing with a channel locks.This will twist off in a counter clockwise manner.
Remove the plastic white shield which lies on top of the ball valve. Lift it right out.
Remove the ball valve by pulling up on the stick. The ball valve rests on the housing and will lift right out.