My first choice to buy Ic51 ink cartridges online would be Amazon.com. Office Max and Office Depot have good deals for ink cartridges as well. www.colortonerexpert.com/LC51Inks sells them as well.
Brother LC51 ink cartridges are available in black, cyan, magenta and yellow so that you can print in color. Many online websites have these replacement cartridges including: Inkcartridges, 123Inkjets and Amazon.
Have you been trying to find different LC51 ink cartridges for your printer? These items may be hard to find at certain stores and electronics retailers around your particular region of the country. If you live in a rural setting, your best option might be to order these types of items online.
LC51 printer ink cartridges can be purchased off of sites such as, Office Depot and Office Max stores. If you need it shipped to you, you may also order from sites like Amazon and the previous sites mentioned.
Honestly, I don't think that you can just go and get them refilled. Your best bet would be to just go buy new ink cartridges for your printer. It's probably cheaper anyway.
Pull the paper tray out. Open the lid. There is a light blue clip on the end. Press it and you can extend the bottom of the tray. There is a part of the lid of the tray that you can extend too. There is no clip. Just force it (gently). Then load your paper and print as normal. There are instructions printed on the bottom inside of the tray, but they are not great.
Brother inkPop-off the color top, removed the clear rubber ball ring/valve. Now you can usual refill kit to poor in the appropriate in color.After filling the ink,replace the above two in reverse order and taped down with clear type.Replaced the cartridge and the appropriate slot... and your good to go!I do have to be honest, sometimes they do leak....There are some think important to be care upon these. Like must use a medical syringe to insert ink into the inkjet cartridges. Must take care the quantity of inkfor different colors. Because more or less amount of ink from certain level may effect the printing performance of the printers.