Step 1 Turn off the power to the light fixture at the main service panel. Step 2 Remove the diffuser to expose the fluorescent tube(s). Step 3 Remove the tube by rotating it. Twist and turn the tube in any direction to disengage the tube and gently slide it out of the sockets. Step 4 Inspect the pins to see if they are bent or broken; if so, replace the tube. Step 5 The ends of a worn-out tube are dark gray. Step 6 Insert the new tube so that the pins slide fully into the sockets, then twist and turn in any direction until the tube is securely in place. Step 7 Reattach the diffuser and switch the power back on.