Shut off sink water with a broken valve?

I need to replace a sink faucet in my apartment.
I was trying to turn off the water using the shut off valves below but come to find that the valve handles are so over used that there are no treads left thus making the handle portion useless.

I need an idea on how to turn off the water to my sink using these valves, since I can't just go outside and turn off the water to the whole apartment.

Or should I just fight through the water (I think I might have to).

If anyone has an idea on if there's just something I turn with a pair of pliers since this thing has no tread left, that would be swell.

Thanks. Anyone with the 'call management' response will be ignored.


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plumbing hampton hill|central heating kingston