There are a couple of ways of doing this, depending on whether you can remember your current password or not.

 

If you cannot remember your password at all, from the login page click on the forgot password link and follow the on-screen instructions.

 

If you do know your current password and you just want to update or change it, then log on as normal and select your profile picture in the top right corner. Then click on the “edit settings” button and then click on the “change password” button.