However, how do I add new admin accounts for integra/im portal mod, and how do I change the password for the current admin account?
Well first you just create a normal account, or have them sign up for a normal account. Then you would go to ACP > User Admin > Permissions > Enter the name of the one you want to make admin > Change User Level : to Administrator
Then if you want the rank to show him/her as admin as well, go to ACP > User Admin > Manage > Enter the name of the one you want to make as admin rank > Scroll Down to Rank and set as Administrator
Secondly, to change the password of the current admin/board founder is the same as any account.
Log in as Board Founder/Main Admin then either go to your own profile and change the password there, or go to ACP > User Admin > Manage > Enter your own name/Admin name > Change password