We have a freightliner with a pusher axle and "poorjoe" just replaced all of the air bags himself. It took about 20 minutes a bag. The biggest pain, I think, lol, was jacking up the rear of the truck.
All I can warn you is: make sure you get the RIGHT airbags.
If you want to speak with "poorjoe" in person, he would be happy to tell you how he did it. Just pm me and I will send you our telephone number or you can email us.
-mcbride-
--What goes around comes around--