How do you change the imadmin password in Identity Manager ?
Identity Manager R14.x
If you can login to Identity Manager with a Users with System Admin rights then you can just go to :
User -> Reset User Password
If you can not access User Console then you will need to login to Admin Console
Environments > Select you Environment > System Manager > Create a new User with System Manager permission.
That User will now be able to login to User Console and change the imadmin Password.