Find an open-ended wrench suitable for the water valve;

Cut off the water valve in Fang Shuijing (the main pipeline before entering the house);

Tap water at the lowest faucet in the house until it doesn't flow out;

It is also possible to find a suitable water receiving container and put it under the water valve to be replaced with several layers of newspapers;

Put the towel on the water valve to be replaced;

Replace the water valve with the found plate. Before replacement, wind the raw material belt clockwise at the thread of the water valve for several times to prevent water leakage.

The above is to replace the building by yourself. You don't know the tool faucet yourself. You can take pictures of the hardware store owner.

Pay attention to close the upstream valve first to avoid running water and difficult operation during replacement;

If it is a steel pipe water valve, unscrew the broken water valve with two pipe tongs or wrenches. The pipe head line should be wrapped with raw material tape to prevent water leakage. Screw on the valve of the same model and size, then open the upstream water valve and check whether the replaced water valve leaks. If it doesn't leak any more, it's ok.

If it belongs to the plastic pipe water valve, cut it off at the water valve interface with a pipe cutter, and cut more, because the pipe was 4 cm in the original welding. If there is no pipe cutter, you can also cut it with a hacksaw. Weld enough length with a welding machine. Welding valves of the same model and size with welding machine must be dry and waterless to prevent water leakage. Then open the upstream water valve and check whether the replacement water valve leaks, and it will be Ok if it does not leak again.