How to delete product groups in bulk and set free the reference numbers

Summary:

Hello, how are you doing?

We have a product catalog today, that has many structural problems. So we are going to create a new one.

The important thing, is that we need to reuse de reference numbers of the groups of the previous catalog (the one that we are going to delete)

I tried deleting a group directly in the app configuration , and then creating a new group with the same reference number, but the system won't allow it because it says that the reference number still exists.

How can we delete all the current catalog groups, but making sure that the reference numbers are deleted too, so we can use them again in the new catalog groups?