I had an issue with papercut where a SMB connection path was saved with the wrong username and password allowing higher then wanted privileges. To change the user to one with lower privileges you can use the Manage Network Passwords from control panel.
Type Manage Passwords in the windows 10 search
When open select the credential you want to modify. In my case the second one highlighted in green. Hit the dropdown to edit the settings.
When you hit edit, you will get a dialog with the name/ip of the server and then you can update the username/password as shown below.