Thanks for the responses. I tried one with some water mixed with Armor All. It was a bit stiff going on and I couldn't get it over the metal ball at the end of the shaft that the rubber goes over.
I tried using a bit of wd-40 on the other and it went on much smoother, and more importantly, all of the way. I would never recommend using wd-40 for handgrips, but it does seem to have worked for the rubber foot rests. The rubber seems to be tight and doesn't move around...probably due to the squeegee effect they had going on the metal shaft...as the rubber went over the end ball, excess lubricant squirted out of the little hole on the outside end of the rubber!
Thanks again!