Properly relieve the fuel system pressure and disconnect the negative battery cable.
Disengage the vacuum line from the pressure regulator.
If applicable, disengage the fuel line(s) from the regulator.
Remove the retaining bolts, then separate the regulator from the fuel rail assembly.

To install:

Install the regulator to the fuel rail and secure using the retaining bolts.
If applicable, engage the fuel line(s) to the regulator.
Engage the regulator vacuum hose.
Connect the negative battery cable, then pressurize the fuel system by cycling the ignition (without attempting to start the engine) and check for leaks.