Hot Water Circulator:

You can easily install a hot water circulator pump by following these steps.
Arrange your tools on a workbench or table so that they are clearly visible. Remove the circulator pump and all the accompanying pieces from the manufacturer packaging and set them up near the tools.
Turn off the main water valve. Switch off the isolation valves for the system line that is fed by the main water control. Make sure that the line is deactivated before disconnecting the existing pump. Turn off the electric power supply. Remove the wires that are connected to the motor and reapply the electrical caps to the ends of the wires. Mark the pipe with a marker just outside of where the existing circulator pump sits on the line.
Place a bucket underneath the marked area to catch any water that spills out when the bolts are removed. Leaving one in place to steady the existing pump and hold it in place.