Stop Identity Manager. If you have deployed Identity Manager in an application server cluster, stop the application on all hosts.
Change the password for the connection user name in the DBMS instance that you are using as your repository location. For example, on MySQL
mysqladmin.exe -hlocalhost -uwaveset -poldpasswd password newpasswd
Change the password that is stored on the DataSource object using the tools provided by the application server, directory server, or DBMS that manages your DataSource object.
Re-start the server and verify that you can login. If you have deployed Identity Manager in a cluster, then you must re-deploy Identity Manager across the cluster. This will distribute the updated web application (which includes the updated ServerRepository.xml file), to all nodes in the application server cluster.