Sometimes doing things in batches is a little bit easier, using the "batch" tool, you can delete & group folks rather than having to edit their profiles individually. To batch group users, simply select all of the users you'd like OR check the box on the top row to select all users on the page.
Next, select the group that you'd like them to be in:
Once selected, click "okay" and they're in the group!
Have any questions? email firstname.lastname@example.org or your customer success manager.