Close the main tap water valve.
Use a 250-30mm adjustable wrench or pipe wrench to turn the old faucet counterclockwise and remove it.
Go to the plumbing equipment (or hardware) store and buy a faucet with the same specifications (the general specifications of this faucet are 15mm and 20mm, yours should be 15mm) and walk around with the raw materials.
Hold the faucet with your left hand and wind it clockwise with your right hand (this is very important, the direction of the ribbon must be clockwise, otherwise it will leak, that is, the direction of winding the ribbon should be opposite to the direction of the faucet thread).
Screw the faucet clockwise on the water pipe connector and tighten it with a wrench.
Open the main tap water valve.