Andy,
At the risk of being appropriatley chastised.... I have resealed a few of these in the field. The top two packings in the truck is what I am talking about. Never this capacity- but I think it is just a matter of scale. The trick is getting the brass collar above one of the seals out as I recall. I can check my teardown pics if you want, but it seems that one gland nut does not have a collar- just the seal. On this one you just pick it out. On the other seal, I chain the free lift from moving, remove the gland nut, start the machine and feather the lift spool just enough to push the collar and seal out. Take the top bracket loose, snap ring-ring- and 3 dogs. Remove and clean gland nuts, sealing area inside tubes as well as possible, grease and slide seals on place. Push one side of seal in and gently work the remaining seal in- pushing with a wooden dowel rod.
Steve