2010 Dodge Caravan Towing with overdrive?

We just bought a brand new 2010 Grand Caravan and my wife wants to use it for driving to a vacation. She wants to tow the wave runners-- together with the trailer- total weight is about 2000 pounds.

She wants to take it to get a receiver put on, but I just looked at the van and I can't figure out how to turn overdrive off. This would be useful too because most of her driving is city.

The owners manual doesn't even mention the term "over drive" but it does say "eco drive" with no mention of how to turn it off.

Any advice would be appreciated.