Below are a few steps showing how this was done from Drupal 7.2.x to Moodle 2.6
Steps taken:
1. Install the ssso auth method to Moodle.
2. Log into Moodle and make sure this auth method is enabled.
3. Create a block in Drupal containing the necessary fields and URL to the Moodle site.
4. Make sure the block is only available to authenticated users.
5. I did not make it available to Administrators since I wanted the two sites to have unique administration access rights.
6- Add custom fields to Drupal for – firstname, lastname, city and country.
Via Miloš Bajčetić