H E L P ? I'm trying to replace the hot water valve on my kitchen sink.
I don't have a lower level faucet, how con I drop the water level in the line
So I can repair it?

I understand your problem, I live in a slab home also. We just shut the water off to the sink and catch the water in a pail or simply mop it up. Do you need instruction on how to install your new valve? If so I need information on the new valve before I can help. Regards, Tom

Are you trying to get the water out of the line so you can solder?
Do you have an outside faucet?

Oh, that's right you said hot water. Close input valve to water heater, open drain valve and let a little water out. You probably need to drain and flush your water heater anyway.

Cream... I think you can pull the stem assembly from the shutoff and then catch that water in a bucket. Should not be a mess as the stem assembly and packing nut are in front and will allow water to flow straight out and into bucket under it. See pic.

If this helped please RATE THIS ANSWER. Thank you.