Remove loose grass and soil from the area beneath the beam that is to be lifted and level the ground. Place a 4-by-4-foot steel plate, at least ¾ inch thick, on the ground where the bottle jack is to be installed to avoid the jack slipping.
Remove any attachments holding the beam that attaches the building to the pier to avoid damage to the beam. Place the hydraulic bottle jack on the steel plate with a ½-inch steel plate positioned between the ram of the jack and the beam before lifting commences.
Turn the valve at the base of the bottle jack clockwise until it cannot move anymore to close the valve, and then insert the handle into the opening at the base of the jack. Pump the handle to lift the ram of the jack until it lifts the ½-inch steel plate and the beam 1/8 inch off the pier.
Build a support structure next to the jack using 4-by-4-lumber beneath the beam to hold the structure in place. The support structure should be built to the same height as the foundation beam when lifted on the jack.
Once the support structure is built, the valve at the base of the jack can be slowly opened to lower the ram of the jack. The repair or replacement of the pier and beam foundation can now take place safely.