What version of Creator are you use?
In Creator 2 Update 1, using Application Server version 8.2, you can do the following..
1) Log into the Admin Console using the default UID/PWD
2) Expand the tree view by following this path:
Application Server > Configuration > Security > Realms > admin-realm
3) Click on "Manage Users"
4) Click on the UserID "admin"
5) enter the new password that you would like
6) Click on the "Save" button on the upper right side of the page.
That should do it for you.
Good luck