Refer to the instructions in How do I remotely authenticate a user using ScreenSteps Remote Authentication? for creating a Single Sign-on endpoint. Make sure to select SAML as the mode when creating the endpoint.

Click on the Upload new Salesforce Configuration file button and select the metadata file you downloaded previously. This file will populate the SAML certificate and the remote login url.

Note that once you have finished testing your endpoint you will need to click the Activate checkbox in order for the endpoint to become active for your ScreenSteps users.