In turning off the supply of water to change the kitchen tap, you have to situate the isolating valves of the supply system of the pipe. You may locate it fitted at the hoses’ outputs. Turn the valve now with only a quarter in turning off the water. Also, try streaming the water to witness is you have turned it off correctly. If the system does not have the independent isolation valve, turn off your water supply from its main stopcock. The moment that you are 100% sure that there’ll be no circulating water, then, you may proceed to its next level.