Excavate the ground where the piers are being installed with a 1 1/2-ton excavator. Dig a trench slightly wider than the footings for the piers, and at least 12 inches deeper than the frost line.
Place the waxed fiber tubes for the piers into the rigid plastic footings. Using the footings allows the weight borne by the piers to be distributed over a wider area, and helps prevent the piers from sinking into the ground.
Place the assembled pier frames (tubes and footings) into the trench at the proper locations. Have the footings inspected if required by your local building codes.
Backfill the trench with dirt to lock the piers in place. Check the footings to make sure they're level as you backfill them.
Place another concrete footing in the top of the waxed fiber tubes. The footing will act as a funnel while you pour the concrete into the tubes.
Pour the concrete into the tubes, mixing it with a shovel every 8 to 10 inches that are poured to remove air trapped inside the tubes. Fill the tubes and remove the footing on the top, then smooth the concrete at the top with a trowel.
Install the metal rebar or metal brackets which will be used to connect the deck to the piers.
Allow the concrete to set for the time specified on the packaging.
Cut away the tubing around the pier with a utility knife, if desired.