A Developer who has never worked in an Agile Setting

Have you talked to your Scrum Master about this since part of their responsibility is to help further the understanding of Scrum?  

How about asking the rest of the Development Team to help with this since they are already immersed in the practice?

As a Product Owner how can I get a developer who has never worked in an Agile/Scrum environment up to speed on being an Agile Developer. How should I go about getting them to adopt agile principles?

You can't. In agile practice you can't "get" other people to do anything. What you can do is to take this issue to the team, and ask how they will support and accommodate their new fellow member when creating "Done" work. They may have ideas on how you could help.

You, for your part, should expect a short-term drop in productivity, and reassure the team that you understand the impact of membership change. Remember that the best way to encourage the adoption of agile principles is to embody them.

Where is your Scrum Master? It is their "responsibility" to coach, train and mentor the Development Team member on business agility. One way you can help is to encourage the engineer's manager to send him to an external Agile or Scrum course that is focused on developers. There are a few of these run by the large Agile training and certification bodies, including Scrum.org.