Removing all subcategories from an existing category

[L30110]

Hmm. Thanks, but that doesn’t seem to work, in fact it messes things up pretty badly. It only appears to impact the top-level category name, and leaves all the subcategories intact. It also only will apply to one item at a time, even when they’re all in theory selected! Which I definitely don’t understand. I can see how to probably do this one item at a time by switching each one to a new category name, deleting the original category with the subcategories, then recreating it without the subcategories and moving them all back in individually, but that is going to be VERY time consuming.