This is a pic of the existing Left Front. The blue lines show the height of the heel, the balance between them and the outline of the hoof. The thin white lines are all bar. When this hoof is weighted, the height of those bar walls jam down at an angle...pinching in under the frog. The white center line is the run of bone. Heel balance is the line that runs between the heels being perpendicular to the bone. So, you can see that the right heel is higher than the left, bar also. The outline of the frog is where the groove is and red arrow pointing to the higher heel getting it harder, so bruised.
This is the same pic. I just saved it and kept going. The horizontal white line is the new height of the heels and balanced. The line going around the hoof is the new wall height, which is correcting the balance back to front. If you look at the new heel line, together with the new wall line, You can imagine the balance by looking at these two lines together and imagining a perfect sunset on the water. The heavy white line going around the hoof under that, is how much that bar needs to be brought down. The bar ramps at the back should start at the front by merging up out of the sole halfway back on the frog and ramp straight up to meet the new heel height dead on. The line in front of the ramps, its height flows forward to be at the height shown.
The picture below that shows the finished trim and what it should look like.
The heavy white contour lines show the new shape of the interior of the hoof in relation of bar to hoof wall.
You can print this pic and take it to the barn with you. You can literally draw the heel balance line where its on the back of the heel platforms right on the hoof and rasp down to meet those marks. You can also do the same to establish the new wall and use it as a guide as well. All the solid white area is a surface that is flat to ground. Then after you arrive on the wall height, the thin black lines shows the bevel on that surface.
Because he's been standing in a stall so long, he hasn't been moving and torquing on that excess growth. His parts and pieces have have stubbornly been able to hold their places, which is an advantage. It means that you can get down to those marks safely and can even go further, but enough change for now. Reverse the rasp in your hand and lay it on the heel platform and pull back towards yourself as you take the heels down, then normally working your way around the hoof, down to the new wall height.
These lines can be identified on the hoof, marked to arrive. The balance will be improved front to back and side to side. Heels coming down a little bit and enough change for now.
It will be good to tweak, like once a week to keep moving towards your goal. His parts and pieces will better define themselves and it will be easier to see after this trim. The goal is to let him get his ducks in order from this trim, so the hoof can talk to you and you can listen, so it will be easier.
The bevel should leave 1/16" of white line still attached to the edge of the sole from 10-2 o'clock on the hoof (center line is at 12 o'clock) and everthing beveled at a 45 degree angle on out from there. On the sides the bevel fades out to only take the outer half of the wall away in bevel and should carry back to include the sides of your heel platforms. (but not the back of the platforms. The heel balance line should look just like I drew it. Straight, balanced and flat to ground and the bevel. (angled short black lines on each side.
Just what you've trimmed so far, I can see the positive reaction. The breakover has come back and the frog, which was stretched forward, is receding back to where the true apex is. The mess in front of the apex, is leftover frog (black) which needs to be cleaned up off the sole....gently, carefully scraped off. What looks to be a hole in front of the apex is the toe wall height showing itself and will be diminished when you arrive at this trim. For now, don't lower the bar any more than what the line shows going around the frog. After this trim, we start slivering the bar with more care.
You can post pics after the trim to see if you "arrived" or in a week and I'll do this again to help you move forward.
It takes me awhile to do this, as I'm not just squaring up lines, but thinking about comfort, balance, the run of bone and many other things. So, it takes time. Best to put patience on your sleeve for me and the horse. The pictures will keep coming on each foot until I get them done for you. If you have any questions, please ask.