Please note that I'm using a Samsung Note 5 but this should help.
That's not where you update your email exchange settings. You need to go to applications>email. There you will see your account. Click on your account>exchange server settings. Here you will see your domain/username and password information. You can now update this and it will flow to whatever application you are using for email/calendar.
I had to change my password at work and everything stopped syncing. I've been trying to figure this out for months and finally figured it out today!