spaghetti code for lunch: refactoring a bunch of fields that always get initialized blah - not even sure if that is the correct way to say it. Basically I have this

public class XmlAccess
{
    public XmlAccess() { }

    public string ApplicationPath = "";

    public string DBServer = ConfigurationManager.AppSettings["DB2_Server"];
    public string DBName = ConfigurationManager.AppSettings["DB2_Database"];
    public string DBLogIn = ConfigurationManager.AppSettings["DB2_User"];
}


I am trying to create some seams for some unit tests and have pulled out a lot of interfaces which is great but I have this thing (code above) trying to initialize all these fields (that's just a sample - it goes on and on...) when it fires up. Anyone have any suggestions as to how to refactor this? I have never had to do this sort of major refactor of "old code" but I am sure others have. The way it is handling those variables is silly and untestable but I am not sure what to do about it and it's holding me up.
Does any code set those fields?

Turn them into properties, then extract the interface that includes the properties. I recommend against letting any code set them, if at all possible.