Bruce,
For obvious liability reasons, I can not tell you to modify your brakes to alter their original configuration. However, if you decided to do this on your own, the only thing that is the least bid technical, is cutting the shaft to the right length. Everything else is just unbolting the old unit and installing the new ones.
I removed the front wheels to make the job easier, and it took about an hour from start to finish. However, I think that you could do the job without wheel removal, but it would be more difficult. I do not see any reason that the average mechanic would have difficulty with changing your front air chambers.
From your last description, you may have over-lubricated brake calipers. This happens if someone greases the calipers without purging the excess grease. That is why I referred you to the Meritor manual for the right procedure. A clay based grease is mandatory, but you also have to use the proper procedure.
Gerald