Normally TestComplete detects passwords and when it does, it creates a Project Level Variable that holds your password.
If this is the case, then you can change the Password variable value by clicking on your Project, then selecting the 'Variables' tab at the bottom of the screen. This will show you any variables created and allows you to alter the 'Default Value' to your new password.
Below is an example of a Password variable found at the Project Level;
Can you answer another question. I have created multiple test in smartbear using different username and password. The issue I am having is that when I change 1 test to use a different password, it changes all my test to use that same password.
How can I have multiple test using different passwords?