Turn off the water supply
Open nearby faucets to drain the line
Dry the pipe completely
Locate the exact leak
Clean the area around the leak
Tighten any loose fittings
Apply pipe repair clamp for a temporary fix
Use epoxy putty for small pinhole leaks
Cut out the damaged section for a permanent repair
Deburr the pipe ends
Install a coupling with new pipe section
Solder the joint if using sweat fittings
Use compression fittings if soldering is not possible
Turn the water back on slowly
Check for leaks
Replace the pipe if damage is extensive