Log in to Facebook and go to Settings > Security and Login.
Click Edit next to Change Password; it’s in the Login section.
Enter your Current Password and your new password twice. If it’s too short, weak, or the confirmation doesn’t match, Facebook will notify you.
When you’ve got a strong password, click Save Changes. You’ll be asked if you want to stay logged in on all your other devices. If you think your account has been hacked, select Log Out of Other Devices. Otherwise, you’re okay to go with Stay Logged In.And that’s it, your password is changed.