How do I delete or edit a document uploaded by a user who is now inactive and no longer a part of the organization?

I am an admin for our organization.  We have a number of clients and one of them is using Adobe Sign and is setup as a group.  When those group users uploaded document templates they gave permissions for the entire organization.  Now a couple of the users in that group are inactive and  no longer employees of the client.  How do I give permission to someone else in that group to edit and/or delete the templates?  I am getting ready to setup another client to use Adobe Sign and will set them up as a separate group.  The issue is they will be able to see the documents of their direct competitor.