We are copying production data down to a test environment. We want to change th

The user accounts are stored in the personalization engine. You will have to develop a process model that gets all user accounts and then use Update User Properties smart service to update the account information.
On a side note: loading data from prod specifically to test is usually not recommended due to security reasons, for example, it is strictly forbidden in Appian Cloud environments. If you have to backload data, we recommend doing it into an environment with the same controls as production. Also, make sure you have sufficient resources, especially RAM, on the target host to handle prod data.

The user accounts are stored in the personalization engine. You will have to develop a process model that gets all user accounts and then use Update User Properties smart service to update the account information.
On a side note: loading data from prod specifically to test is usually not recommended due to security reasons, for example, it is strictly forbidden in Appian Cloud environments. If you have to backload data, we recommend doing it into an environment with the same controls as production. Also, make sure you have sufficient resources, especially RAM, on the target host to handle prod data.