You can log in and change this from the 'User Management/Application Users' menu.
Alternatively, you can do it from the CLI if you are locked out.
There shouldn't be any problem with that. It's generally best to set that account to an unknown password and have other administrators use their own accounts with appropriate group membership to perform admim tasks.
In some cases an engineer might have used the ccmadmin account for services - e.g. such as UCCX AXL access, or some other similar case. What they should have done is used specific service accounts with appropriate rights.