2005 Mercury Marquis Air Suspension

I just had my rear tires changed at a local dealer.
Before starting the work, he turned off the air suspension switch located in the trunk of the car.
Everything was operating correctly going home.
The next morning I drove my car. While driving, it felt like I was in the old U.S. Army jeep. The suspension was locked. So, I stopped to see if the suspension switch was turned back on, it was. My question is, how do I release my suspension to make it operate normally?