Call or write to the publishing company the editor works for to see if you can talk to them. You may be able to reach an editor directly by asking to speak with them at work. Send a formal letter or place a friendly call asking to speak with the editor. Ensure that you’re able to articulate why you want to speak with them ahead of time by practicing the conversation.
There are a lot of editors out there with no actual editing experience working with a publishing company, newspaper, journal, or other business that requires a high level of expertise and provides training for editors. Without working in such a position, it’s very difficult to obtain and master the skills required to become a great book editor. It’s not impossible, but it is unlikely.