I. Lighting the pilot is pretty much the same process with most standing pilot appliances: depress the ON/OFF/PILOT or control valve knob slightly and turn it to the PILOT position.
II. Next, push in on the same knob with one thumb while clicking the piezo igniter button repeatedly with the other until the pilot lights (the thumb pressure holds the gas line open until the pilot flame can heat up the thermocouple/thermopile, so you need to keep the knob depressed for about 45 seconds, so the thermocouple/thermopile has time to start generating before you can let go of the thumb pressure). If the pilot goes out when you remove your thumb, it means the thermocouple/thermopile didn't heat up enough to hold the gas line open, so wait a couple of minutes and repeat the process until the pilot stays lit with your thumb removed.
III. Once the pilot remains lit when you stop depressing the knob, turn the knob to the ON position.
IV. Now you can light the burners with the manual switch, thermostat, or remote control unit