The easiest way I know of to deflate air bags is to do on purpose what often happens by accident. That is, raise the body of the car with the trunk switch in the ON position until the rear wheels are off the floor. This will cause the bags to vent because the sensor is extended and thinks the body of the car is too high. You may need to also turn the ignition switch to the ON position if the car has not been run for a while. Turn the trunk and ignition switches OFF after the bags deflate. At that point you can remove the solenoids, bags, etc. without them being under pressure.

To reinflate the bags, turn the ignition and trunk swithches ON and SLOWLY lower the car to the ground. The bags will begin to inflate when the car goes below trim level.

The above method is very easy to do with the carlift I have in my garage. I used it to replace the bags on my 1999 CV. However, it may be tricky to do without a lift. That said, if you don't have a lift, you could put the front of the car up on jackstands and have two people operate floor jacks simultaneously to raise and lower the rear. Put the floor jacks on the frame, not the rear axle, and replace the floor jacks with jack stands after the car is raised. Good luck and be careful.

Piranah and RF, I don't think that will work, you have to hit the vent solenoid as well.