Turn the Jacuzzi off and switch off the circuit breaker powering the tub.
Unfasten the access panel near the bottom of the Jacuzzi with a Phillips head screwdriver. Turn the valves inside the Jacuzzi compartment clockwise to drain the bath.
Unfasten the retaining screws in the grill over the defective jet using a Phillips head or star screwdriver, whichever is applicable. Pull off the grill and set aside.
Pull out the rubber gaskets by hand or use pliers to expose the jet completely.
Grasp the jet with pliers and turn counterclockwise until the jet is free from the stem. Fasten the new jet into place, then replace the gasket, grill and turn the power back on to finish. Repeat as necessary for other defective jets.