1. Close the angle valve under the toilet tank (some people call it "eight-character door");
2. Clean the water in the toilet tank;
3. Remove the snakeskin hose from the water inlet of the water tank;
4. Unscrew the cover clockwise from the bottom of the water inlet of the water tank to take out the water inlet valve from the water tank.
Water tanks have various structures, so you'd better spend a little money to ask a plumber for help. Otherwise, it may be removed and cleaned up, so you can't install it!