Since you did not mention which engine you have, the only help that I can offer you at this time is a link [http://www.justanswer.com/car/09ur0-explain-change-timing-belt.html|to a site] that will explain how to do the complete exchange and how to set up the timing. You can download the service manual for your vehicle [http://www.keepandshare.com/doc/3289580/mitsubishi-eclipse-service-manual-pdf-november-20-2011-5-57-pm-79-5-meg?da=y|right here] Page 11F11 of the manual will go through all the steps. Good Luck.