The only way to get him out of there safely is to take the whole seat out. If you can use a socket set, you can do it.
The main bolts go right through the floor panel, you'll have to get under the car to get them out. Once you get the seat unbolted, you can lift it out and turn it over to unfasten the ac duct and get him out.
It's not nearly as hard as you think, I've done it several times, and I'm a 38 year old woman! Best of luck.
Gale
Most cars you can do it from under the seat INSIDE the car. I've been wrenching on cars for 15+ years and have never had to go under a car to get a seat out.