How to Refill a Zippo Lighter
To refill your Zippo, you'll need to take it out of its case and gradually pour lighter fluid into the bottom. First, grip your Zippo by its chimney and pull it out of the surrounding case. Insert a screwdriver in the hole in the middle of the felt bottom and lift it up. Once you've exposed the cotton balls inside the lighter, insert the nozzle of your lighter fluid into the Zippo and pour for 3-5 seconds. Wait another 5-10 seconds for the cotton to absorb the fluid, then pour again. Repeat the cycle until the cotton at the top of the lighter is wet. Then, close the felt bottom and return the lighter to its case. If you spilled any fluid on your Zippo, wipe it up with a paper towel.
Open the lid of the Zippo and remove the inside unit from the case. Firmly grip both sides of the flint wheel with your thumb and index finger. Hold the bottom of the Zippo lighter with your other hand and pull up on the metal to remove the unit from its case. The flint wheel is the grooved circle that you turn with your thumb to create a flame. The metal box should come out fairly easily, but if it's never been removed before, you may have to pull a bit harder the first time to get it out. Turn the inside unit over to reveal the felt bottom. The bottom of the unit should include a small hole in the middle of this felt pad and words written across it. The words should read “Lift to Fuel.” You may also see a small flathead screw on the side of the pad. Remove the felt bottom and expose the packing material in the unit. Insert a screwdriver into the small hole in the felt bottom. Once it's lodged in the hole, pull up on the bottom to lift it away and reveal the packing material inside. If you don't have a small enough screwdriver, you can also use an unfolded paper clip. Insert the lighter fluid can nozzle into the packing material opening. If you've purchased a large lighter fluid canister, you may want to transfer some to a smaller squirt bottle in order to control how much fluid you release into the lighter. Make sure the lighter fluid nozzle is set to “Open” before you begin. Lighter fluid can be obtained at most drug stores and home improvement stores. High-quality Zippo brand lighter fluid is suggested for optimal performance. Squeeze the can to squirt a small bit of fuel into the packing material. Gently squeeze the can for about 3-5 seconds to avoid spraying too much into the insert. Do not squeeze all the lighter fluid onto the cotton at once. The cotton takes a couple seconds to absorb the fluid. If you release it at one time, you will make a mess. The best location to refill a Zippo is over the sink where cleanup is easy. Do not refill your Zippo lighter over finished wood surfaces or other surfaces that could be damaged by contact with lighter fluid. Wait 5-10 seconds, then squeeze the can again to add more fluid. Repeat this step as necessary to continue adding lighter fluid to the cotton. Remember to use a gentle touch when squeezing the fluid can. It's important to wait a few seconds to allow the lighter fluid to adequately soak into the packing material. Stop filling the lighter when the fluid reaches the top of the material. Once you can see the top of the cotton packing material getting wet, stop adding lighter fluid to the unit. The longer you've gone without refilling your Zippo lighter, the more fuel you'll need to add before it's full. For example, if you haven't refueled your lighter since you first bought it, you may need to squeeze lighter fluid into the packing material 4 or more times before it's completely filled. Close the felt bottom and place the unit back inside the case. Insert the unit into the top of the metal case, then push down on it to completely insert it. Continue applying gentle pressure to the top of the insert until it's secure. Wait 1-2 minutes, then strike the flint wheel to light the zippo. Let the Zippo sit and absorb the lighter fluid for 1 to 2 minutes. Then, try lighting the Zippo to see if it's completely refilled. If it doesn't light, go back and add more lighter fluid. While you're waiting for the lighter fluid to be absorbed into the cotton, wash your hands to make sure you don't have any lighter fluid on them. Strike the flint wheel at least 3 times before giving up and adding more lighter fluid to the Zippo. Refrain from using butane or charcoal lighter fluid. These alternative substances will not be as effective in your Zippo lighter and may not work at all. For best results, go with a lighter fluid specifically designed for use with Zippo lighters. Clean up any spilled lighter fluid as soon as possible. If you spill lighter fluid onto the outside of your Zippo lighter, it may damage the finish. Clean it up with a sponge dipped in mild soap and water. Do not run your lighter under water to clean it off; you'll want to avoid getting water inside it. Replace the flint every 1-2 months to keep your lighter working well. Flints will become damaged or worn over time, so they need to be replaced on a regular basis. Use Zippo brand flints for best results, since these are designed specifically to be used with Zippo lighters. 
Open the lid of the Zippo and remove the inside unit from the case. Turn the inside unit over to reveal the felt bottom. Remove the felt bottom and expose the packing material in the unit. Insert the lighter fluid can nozzle into the packing material opening. Squeeze the can to squirt a small bit of fuel into the packing material. Wait 5-10 seconds, then squeeze the can again to add more fluid. Stop filling the lighter when the fluid reaches the top of the material. Close the felt bottom and place the unit back inside the case. Wait 1-2 minutes, then strike the flint wheel to light the zippo. Refrain from using butane or charcoal lighter fluid. Clean up any spilled lighter fluid as soon as possible. Replace the flint every 1-2 months to keep your lighter working well. 