IMO, this is a job for an experienced trimmer. Do you have someone that can come out? Not a simple job and not a quick fix. I don't think that I would attempt that by myself.
However, there is certainly not much that people can help you with unless you post more and better pictures. A full shot of the horse, standing square - at least one pic from the side. The hooves from the side (90 degrees) with the camera at ground level. Again from the exact front and the exact back. Pictures taken on an angle other than dead one front/back and right angles from the side can be very deceptive. A picture of the bottom (sole) of the hooves. And a picture taken when the hoof is held up, looking from the heel to the toe. -- like looking "down" the centerline of the bottom of the hoof.
Ensure the hooves are clean for each pic and the horse standing on clean, even and level ground (cement is great).
Wow. I hope this horse can be helped. Please keep us posted on what you can do for this horse and his/her progress.