How do I fix / replace the band or gears seen thru the scanner glass?

Actually a Workforce 615, but similar to 645. Cleared paper jam and now error message can't get rid of to turn on and off or go to Epson. com. nothing works. When turning printer on now, there is a loud noise and it seems to be coming from the belt/ gears visible under the scanner glass. How do I repair it? Or not worth it?