You should make sure to change your password regularly to keep your software as secure as possible. To do this, simply click the Password icon in the upper right corner of your account card. This will expand the card to show you a traditional password change dialogue.
You’ll need to enter your current password and then your new password in their respective boxes. If you’re unsure of what you typed, click the Display icon to display what you’ve entered, but make sure nobody else can see. Once you’ve entered what you need, click Save to save your new password.