To change your TransferWise password, login to your profile and click your name by the green "send money" button at the top-right corner of the page. Then, select "settings".
Then, click "password" on the left side of the page that follows. Simply enter your current password and confirm your new password twice. Once you click "save", your password will be updated. See how below!
You can also change your password on your mobile device by clicking "forgot your password?" below where you usually enter your password to login.