Corrective pruning often requires on-site guidance by a trained arborists, horiticulturist, or forester. I say that because it is nearly impossible to articulate some recommendations and procedures via an internet forum such as this.
Therefore, I would strongly encourage you to contact your local Extension office to see if they have a professional on staff who could personally assist you. They may or may not have a horticulturist or forester on staff - if not, they should be able to provide you with a list of local arborists.
Best of luck!