There are different styles of toner cartridges used in laser printers, but you can refill most of them in similar ways. Toner in a laser cartridge is used up over time, as prints are made, and you can replace the cartridges to get more toner into the printer. There are some toner cartridges, however, that can be easily refilled rather than simply replaced. These typically have a refill hole that you can open up to fill them, though doing so without proper training can create messes and potentially void the warranty on your printer.
Removing the Cartridge
One of the first things you usually need to do to refill a toner cartridge is remove it from your laser printer. Read the instruction manual that came with your device to determine the best way to remove the cartridge from it. This is usually quite simple, though you may need to press a release button or move a lever that normally keeps it in place. You should also be careful of any toner on the outside of the cartridge, as it can easily stain your clothes and the area around your printer.
Cartridges with Refill Holes
Some toner cartridges are designed to be easily refilled, often having holes in them into which toner can be poured. These holes are usually clearly visible on the cartridge and typically have a stopper or plug that you can remove. Refill kits provide toner in small bottles that include funnels or narrow tips, making it easy for you to place the tip into the refill hole without spilling it. The toner itself is powder so fine that it moves much like a liquid, and it can easily be poured into the cartridge.
Making a Refill Hole
There are also toner cartridges that do not have refill holes in them, since they are not designed to be refilled, only replaced. You may be able to create a hole in such a cartridge by using a hot object to melt its plastic case. Some refill kits suggest that you do this, but you should be very careful about doing so. Such changes are likely to void any warranty you have on a printer cartridge, which means you will need to pay for a replacement cartridge if you damage it. Improper placement of the hole can also result in toner spilling out inside of your printer, causing damage that might not be covered by your warranty since the hole you created likely violated it.
Choosing the Right Toner
When refilling toner cartridges, it is important to choose the right type of toner for your particular printer. There are guides you can follow when ordering a refill kit to ensure the toner is compatible with your machine, and the manual that came with your printer may also indicate what toner to use. If the manufacturer of your printer sells refill kits for toner cartridges, it may be best to use one of these to ensure you get the right toner and equipment for your hardware. Once the cartridge is refilled and the hole properly sealed up, simple replace it in your machine as instructed in the owner's manual.
Calibration and Resetting Counts
Many laser printers need to be properly calibrated and toner cartridges within them must be aligned prior to printing. After you refill and replace the cartridge, be sure to run any setup procedures as appropriate to ensure clean, aligned printing. There may also be a page counter on the cartridge that needs to be reset to indicate to the printer that the toner has been replaced. The instruction manual for your device should indicate how to do this.