Thanks all... The swap out went very easy. Great idea about adding grease. The new hub assemblies came with speed sensors already installed so I didn't look inside. I pulled the sensors out of the old hubs, and the hub that was making noise had a lot of metal from the bad bearings, and no visible grease. The other side was clean inside, but pretty much dry.
This is my 4th Ram, and the first time I have ever had a wheel bearing problem. The other three had well over 150 thousand miles each when I traded them off.