CMS DB password reset on unix

We have changed the password cms db password but the BO services are still using the old password and hence unable to start.

I know with running cmsdbsetup.sh script we can update  but I am reluctant to use it without fully understanding its impact. When I run it does it recreate the entire repository? Or does it retain the repository with a chance to change the log in crendential?

The Admin guide suggests just to run it while installation, it does not say anything about  scenario like mine.

BOE version - XI 3.1

OS - unix

RDBMS - Oracle

Any suggestion would be greatly appreciated.

Thanks!

Ashok