I'm not being stupid, you just change it. How ever it is installed, threaded on, sweated or compression fitting, remove and replace. I'm assuming water. There is another shut off valve further down the line. If it is the main shut off in the house, there is one at the meter. Shut the water off, drain the pipes and change it.
Shut off valve at the wall? Turn the main water line off and change it. How you change it would depend on what type it is and how it attaches to the pipe.
This depends what shut off valve is in question here. Where the leak is and what type of material is the shut off valve made of.
change the (pvc) valve
the hot water valve shut off valve shuts off the hot water. The cold water valve shuts off the cold water. ;()
The gas shut off valve is currently in the off position.
Shut the water off at the main shut off where it comes into the house or at the meter and change the valve at the fixture. The valve at the fixture may be sweated on, compression, or threaded.
Is the shut off valve in your plumbing system leaking?
Is the water shut off valve leaking in your home?
If you have a leaky toilet shut off valve, you should first turn off the water supply to the toilet by locating the main shut off valve. Then, you can try tightening the packing nut on the shut off valve with a wrench to see if that stops the leak. If the leak persists, you may need to replace the shut off valve with a new one.
What to use to solder a shut off valve
Yes, the shut off valve is leaking through the stem.
An air-intake engine shut-off valve regulates air-flow to the motor, and operates as an emergency shut-off valve. There are also shut-off valves on water hoses, so shut-off valves really control the inflow of any liquid or gas.