Lexmark Toner Refill C500, X500, X502N
Refilling your empty Lexmark cartridge is fairly straight forward. Remove 2 screws, lift off the roller and refill through the slot.
You will require a #0 cross head screwdriver to remove the screws. The screws are screwed in fairly tight but can be removed.
Alternatively you can use Method 3 to also fill this cartridge.