Turn the gas lamp's burn lever to the "Off" position.
Light a match and hold the match just under or above the mantle of the lamp. Check the instruction manual for the appropriate directions. Most mantle's have a small hole on the top or bottom on the lantern. Hold the light right outside this hole.
Turn the lever to the "On" position. Allow the lamp to catch the flame. Move the match once the lamps flame is bright and white.
Turn the lamp off by pressing the lever to the "Off" position.