Lexmark optra t610 invalid refill error change cartridge......how do i reset the printer to disable the error

The error may not be specifically a toner cartridge problem but may be due to a stuck cover open switch on the printer. Perhaps this article on Error: "Invalid Toner Cartridge" or "Invalid Refill" will be able to determine the root cause of the problem. Just click on this link: http://bit.ly/dupj2m. Just make sure you are using a genuine Lexmark toner in the printer. If you need further assistance, you can also contact Lexmark technical support. Thanks.