The documentation for pathauto states that if we install Path Redirect and new 'update' button will be available to update existing aliases. I cannot find this update button.

Despite that, what I am trying to do is this: I want to restructure my automated aliases definitions. This will affect 1000s of current entries. After, I want to 'update' these so that the old alias is kept and redirected to the new alias. Currently, the only thing I see to do is 'delete aliases' and then 'regenerate in bulk' - but this is not what I want to do. Path Redirect doesn't remember the old aliases after I delete them from Path Auto.

What is the correct workflow to be able to achieve what I want to do?

Thanks!