Solman not using Z Multilevel Categorization Schema

Hello,

We are configuring the Service Desk in Solman 7.1 SPS 8 and stuck in Step 2.3 Configure Automatically - Activate Categorization Scheme as it throws the below error -

Error: transaction type SMIN has already been included in the categorization schema - SAP_SOLUTION_MANAGER_TEMPLATE.

We have already copied the categorization schema - SAP_SOLUTION_MANAGER_TEMPLATE to Z_SAP_SOLMAN_TEMPLATE and now both are in active status in Z_SAP_SOLMAN_TEMPLATE we have specified the ZMIN T/Type and system is not allowing us to delete any of schema (as shown below becaus delete button is grey out) and we can't change the standard schema to use Z transaction type as it throws error that transaction type already used.

Where can we specify that use categorization schema Z_SAP_SOLMAN_TEMPLATE only instead of SAP_SOLUTION_MANAGER_TEMPLATE.

Thanks

SAP Guy