I have a old kitchen kitchen faucet with attached sprayer. I want to install a Culligan undersink filter which comes with a water faucet that REPLACES the sprayer. I have very limited room under the sink to work in. I cannot even get any normal open end wrenches/adjustibles to work with limited space.

How can I make the sprayer not usable? I assume there is always water pressure going up through the sprayer hose, so just cutting it off is not an option.

Any help would be appreciated!