Whats an easy way to find eastern backhand?
An Eastern backhand is very similar to the Western grip, only you hit the ball with the other side of the racquet.
I also use an Eastern forehand grip on my non-dominant hand for my 2HBH, but I also have my dominant hand in an Eastern forehand grip. Like you, I use an Eastern forehand, so I find it very easy to use the same grip on my 2HBH. Sometimes I can have trouble with high shots, but I try to time them so I can take them on the rise. Also, you usually have to close up your stance, which takes a little bit more time than, for example, a SW grip on the non-dominant hand.
EDIT
Sorry, I misread your original post. So, a lot of my post is not useful for this situation. Again, sorry about that.