From the navigation menu , tap Settings and privacy.
Tap Your account.
Tap Change your password.
Enter your current password.
Enter your New password.
Enter your new password again to Confirm password.
Tap Done to save your changes.
Note: If you can log in but can't remember your password, you can send yourself a password reset email from the password settings page. Additionally, you’ll be logged out of all your active Twitter sessions, except for the one you use to change your password.