First turn the water off at the valves underneath sink.If there are no valves under the sink,shut the water off at the mainline coming into the house.Open existing faucet to drain water from lines.
Also open up a line somewhere lower than you’re working to completely drain the line.Remove old faucet by unscrewing the nuts underneath the sink. Disconnect the waterlines from faucet. If water lines are equipped with shut off valves and supply lines.If ther aren’t any shut off valves under the sink. Cut the half inch pipe with pipe cutter or sawzall.
Install compression valves with adjustable wrench or you can solder new valves on if you have the ability.It’s much easier to use the compression valves.Hook up supply lines to your new faucet.Slide faucet into place,and tighten faucet nuts.Attach supply lines to faucet and valves.Turn new valves into the off position.Then turn the water back on at the mainvalve.Turn new valves to the on position and check for leaks.
I would then remove screen from end of spigot. Turn faucet handles on and let the air circulate out of the lines and any dirt that may half blown up with the water.
Replace screen and enjoy.