Use a butane refill can with the correct nozzle
Work in a well-ventilated area away from flames, sparks, and heat
Turn the lighter upside down
Find the refill valve on the bottom of the lighter
Purge any remaining air from the lighter if needed
Shake the butane can briefly
Press the can nozzle firmly into the refill valve
Hold the can and lighter together for a few seconds
Repeat until the lighter is full
Wait a few minutes before using the lighter
Adjust the flame if the lighter has a flame control
Check for leaks before lighting