Replace the diesel engines with something running on hydrogen? HaHa.

Semi-seriously, why not make some more Cabbages for regional trains that don't have cab cars for use in push mode? Perhaps they are worth slightly more than scrap value?

Reduce (can't do that; already built), Reuse (what can be done with the shells minus original powertrain?), Recycle (cut up and send (or even ship intact) to China, most likely).