When you register, the website automatically generates a very safe password. You may change your password by logging in with the generated one and then editing your profile. When you login you will be in the Dashboard. On the left margin, you will find an icon for “Profile.” Scroll down until you see the two fields for password. Enter your desired password in both fields and click the button “Update Profile” at the bottom of the page.
If you are in the site and logged in, you can find the Dashboard this way.