You will receive a low toner message when it is time to change the toner. Let’s see how to change toner on Brother printer. First, turn on your printer. Then, open the front cover. You need to remove the toner cartridge from the printer. There must be a green lock lever, push it. Now, carefully unpack the new toner cartridge and place it in the assembly. You should be able to hear the click sound while closing the lids indicating that everything is set in place.