Try these steps I found using google search results:
1. Open the front panel.
2. press the clear button (display will show: replace drum 1.yes 2. no)
3. press the * star button, NOT the # button.
4. you should see "accepted" on the panel.
laser printer - Brother MFC7360N keeps saying "replace toner" - Super ...
superuser.com/questions/783439/brother-mfc7360n-keeps-saying-replace-toner