Just make sure you clarify which account does which job, there are three main admin accounts;
1. The SuperAdmim allows full admin access to the Security Console which has a URL something like;
https://rsa01.company.local:7004/console-ims
The server name (e.g. rsa01.company.local) should be an FQDN that is resolvable
We often name this user admin, but you could call him any name including rsaadmin.
If you have SSH access to Linux you can create a temporary SuperAdmin to get you into Security Console
2. The Operations Console is for things like replicas, external Identity Sources and backups, and the URL is something like;
https://rsa01.company.local:7072/operations-console
Typically we name this operations console admin 'ocadmin', but it could be anything including rsaadmin. If you have access to the Security Console, you can add or change operations console admins under Administration.
3. Operating System access account, which is used in the Suse Linux Operating System either through physical or virtual console access or via SSH if that is enabled.
SSH access and this account is enabled in the Operations Console. Typically we name this account as rsaadmin, but again it could be anything. By default we support only 1. As Ed pointed out the supported place to change this password is in the Operations Console, but as Hussein pointed out, you could change it in Linux with passwd. There are some various ways to reset this password if you do not know what it is, but you need console access
