Is it possible to update existing Reporting currency conversion

Summary:

We have established a reporting currency ledger for all our subsidiary countries, converting from local currency to USD at the balance level. We have configured the Period Average Rate and Period End Rate with the Corporate rate type. As we are now implementing EPM for our consolidation, we wish to change the Period Average Rate to a User type rate code (New Custom User rate). Could you please advise on how we can modify the existing conversion type configuration or how to disable the current one or update?

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