Hi @Simon L.,

In IFSAPP10 you need to change IFSSYS password from IFS Middelware Server Admin Console. The option to do this is no longer available in installer like in earlier versions. 

Login to IFS Middleware Server Admin Console and navigate to Common → Database and click on “Change password” icon.

This will open a dialog as shown in below picture. The first option only changes the password in Middleware Server configuration while the second option changes the password in both Middleware Server and the database. 

Changing IFSSYS password would trigger a restart of the IFS Middleware Server which would make the application unavailable for some time. So you need to do this during a proper maintenance window. 

Hope this helps!