I think the answer to how to propage Eremurus is "very carefully"! First, you'd have to wait until they were dormant before disturbing them. They have long, octopus-tentacle-like roots that spread out sideways, so digging them up without breaking roots off could be tricky. Then you'd have to use a sharp knife to divide them, making sure that each bud had at least a couple of roots to sustain it. It might be advisable to let the cuts air-dry to seal the wound before replanting. That's how I would go about it. I have not actually attempted doing this!
