Task: change sand in a hayward sand filter
Assumptions:
Change sand in a hayward sand pool filter.
Steps:
Turn the hayward pool pump off
Take off the drain cap
Remove the multiport valve
Remove the collar
Take off the valve
Sand entry can be prevented by sealing the stand pipe with duct tape
Use a bucket  to remove the sand
Rinse the inside of the tank to remove any remaining sand
Reattach the drain cap to the filter tank's bottom
Fill the tank with water halfway
Add the sand
Change the sand-pipe
Replace the multiport valve on the stand pipe