Mass modification of product Teams and Access Control Rules

Does anyone have a process for mass modification of context Teams [Roles along with the groups/individuals assigned] and product/library access control rules (ACR's)? The modification must include deletion of existing Roles and ACR's. A simple way to view this is applying a new product template to an existing product replacing the existing Team and ACR's. I did not see a way to delete existing Roles or ACR's using LoadFromFile, but I admit it's not a tool I'm very familiar with using.

Can the Windchill Bulk Migrator export an existing product and re-import it back into the same system using a different product template?

Regards,

Dan N.