Just to be clear, the exact step you're missing is just a factory reset of the Z-Wave device rather than an exclusion. This should erase its memory of the Z-Wave inclusion (there are apparently old GE switches where this doesn't, but that's the only such report I've seen; there may be others). The alternative is doing a general Z-Wave exclusion, which you can do with any hub/controller--just not the one it's currently paired to, or as you note, it will be removed from that hub.
An alternative is just to pair it like a brand new device (again, you'd need to reset it or exclude it somehow first), then use the Swap Apps Device feature to replace references to the old device with references to the new one. I've "historically" had better luck with this than the Z-Wave Replace feature, but either should get you the same outcome (I say "historically" in quotes because this feature is new, but Z-Wave Replace has been mixed for me in the past; others have reported better luck, and the recent radio firmware update can't hurt).
Not sure about your ladder, though.