I've done this myself with a Deore XT hub - quickly cut all the spokes out. Then got the spanner and cassette lockring tool to remove the cassette and had a "ah....that was not clever" moment. Ended up putting the handle of the chain whip in the bench vice and with a faff got the lockring off. Live and learn.
Do recall that some sprockets on the Maillard freewheels could unscrew.
Do recall that some sprockets on the Maillard freewheels could unscrew.