Eclipse owners can request a copy of the owner's manual for newer models from Mitsubishi's website or through their local dealer. If your vehicle is an older model, you might find a used copy for sale on some online shopping sites.
According to Edmunds.com, you may be able to order a replacement manual from your local dealership; the cost is around $25-$40, as of 2013. Mitsubishi offers downloadable PDF versions from their website at no cost. Access to these require a free user account and only manuals for 2010 or newer models are available. There are also some previous owners who have held on to their older manuals and now sell them on eBay or Amazon.