In your Dashboard click on My Account and then choose Settings:

Under Password (upper right corner) click on the edit button:

You can then change your password:

1. Enter the old password

2. Enter the new password

3. Confirm the new password

4. Click SAVE

You have now successfully changed your password.

We recommend you to  change your password regularly and never re-use it. Read this article on how to create a safe password.