Sometimes the Brother printers at the cashier stands continue to show a "Replace Toner" message after the toner has been replaced. Luckily, there is a simple solution to this issue:
1. Open the front of the printer
2. Press the Secure and Cancel buttons at the same time (on some models, these buttons may need to be held for a few seconds)
3. The screen should display "TNR-STR"
4. Press ok.
5. Press the up key to reset. The screen should display Accepted.
6. Close the front of the printer back up and resume normal operation
A video that outlines this process can be found here. As always, if these troubleshooting steps don't resolve the issue, don't hesitate to submit a ticket to IT to troubleshoot further.