There isn't an option within the program to change the password. You have to choose the "I forgot my user ID or password" at the Sign in screen. That's the only way to change password other than when the program prompts for a change.
I think if you log in here https://accounts.intuit.com/index.html
instead of here https://www.intuit.com/sign-in/
You can change your sign in info, privacy settings and stuff...I dont know why they need multiple places to do different things, everything should all be in one place.