Here are the steps to follow:

1. Locate the gas control valve on the bottom of the water heater. It will have a knob with the settings "On," "Off," and "Pilot."

2. Turn the knob to "Off" and wait for at least five minutes to allow any residual gas to dissipate.

3. Locate the pilot light assembly. It is typically located near the bottom of the tank and has a small tube connected to it.

4. Turn the knob to "Pilot" and hold it down. While holding the knob down, use a long lighter or match to light the pilot light at the end of the tube.

5. Continue holding the knob down for about 30 seconds after the pilot light ignites, then slowly release it. If the pilot light goes out, repeat the process.

6. Turn the gas control valve back to the "On" position.

7. Finally, test the water heater by turning on a hot water faucet in your home. If the water heats up, then the pilot light was successfully relit.

It's important to always follow safety precautions when relighting the pilot light on your water heater. If you are unsure or uncomfortable with the process, or if the pilot light does not stay lit after multiple attempts, it's best to contact a professional technician for assistance.