How to Rename MSSQL Database User in Plesk Panel 12.5?
You can change the existing MS SQL database username following the steps given below.
Step 1: Enter your username and password to Login to Plesk panel.
Step 2: Under Databases, click User Management.
Step 3: All the database users are listed over here. Click on the required user to be changed.
Step 4: Provide the new username in the Database username field and click OK.You can also change the password, roles and privileges of the selected user here.
Respective username and other changes will be changed as shown in the below image.