Is there a way to release the air out of the suspension?
The easy way is to let the bags just go down on their own.
A quicker way is to disconnect the links to the three valves and let them down but that is a real pain and you need to be sure to block between the air chambers and the suspension. If you have a pit it is not so hard but there is not enough crawl space under the bus once the bags are down and you sure don't want to go under there to let them down.
It is possible to let the rears down by pulling down on the valve arm once the links are disconnected (If you have long arms, or you could use a stick or long rod) but I don't think that can be done from the front. The rear links are fairly easy to reach with the outside duals removed.
What are you planning to do when they are down?