It takes a lot of experience and 'feel' to teach either a green horse or re-train an older horse. Also, I probably don't have to mention this because your muscles are already sending messages to your brain but it takes a while to get oneself properly back to 'equestrian fitness' and regain the strength required to school a horse. Your horse should now be neither heavy nor light on your hands and should maintain this throughout all changes of direction and transitions. Remember, you must think of the horse as being between your leg and hand and you should not feel that you are forcing the issue. Hope all this helps and please send me an email to let me know how you get on.
Feedback is always interesting and useful.