OK guys...just finished the second head rest and this one was much easier and only took 45 minutes and that was stopping to take pics and also i had to reattach the bracket three times to get it perfect. Here's the detailed info with pics:
Remove your stock head rest and take it inside where its easier to work.
I noticed on mine that the stitching was not perfectly aligned around the headrest so i did not want to use it as a reference for leveling. I did try to center the monitor between the vertical seams, but for the horizontal line to start with, i put my headrest posts on a flat surface and used a level while holding the bracket in place (three hands helps with this part). I used a pencil and just made a line all the way across the top of the bracket. Also make sure to account for the lip of your bracket to make sure everything stays between the vertical seams or else you won't be able to get it to look recessed.
Using the template that should have come with your monitors, hold it in place and draw an X from corner to corner, leaving about 1/2 inch from going all the way to each corner.
Now take a deep breath and use your box cutter or utility knife to cut on your X. Pull the four triangles of cover back and out of the way.
Using your template again, take your blade and cut out the box for the screen bracket. I cut mine about 1/4" smaller than the box all the way around just to be on the safe side. You can always trim out more, but you can't put it back
I have found that with a box cutter and the blade all the way out, you can put the blade all the way in and cut. This will cut the foam about 3/4 to an inch deep. Then just pick out the middle of the box with your fingers. It doesn't have to be perfect, but once again, try to make it level, try your bracket fitment, then try more if its not right. Don't get too aggressive too soon.
Keep removing bits of foam from the bottom and sides of your foam square until you can put your bracket in the hole (with the triangles of cloth folded back in), and it takes a little force to get the bracket to recess inside into the cloth. This is also the point where you want to make sure you hole is as level as possible on the bottom. Its ok if it doesn't make contact with the foam all over, but the main thing here is that you want to be able to get the entire bracket to recess into the cloth without bending or warping in one corner, otherwise your screen wont sit flush or may not snap in at all.
Once you're satisfied with your cutout, its time to prep your bracket. The good thing about the method i used is as long as your monitors came with flush mount brackets, these instructions are universal. Mine are Kenwood models and they have a plastic flush mount bracket. The brackets for mine came with 4 holes drilled, one in each corner. We are going to use zip ties to secure our bracket to the seat, so what you want to do is drill another hold about 3/8" to the inside of the existing holes. If your bracket has none, then obviously you will want to drill two holes in each corner. Make sure the holes are horizontal. Also, very important....make sure that your holes are big enough so that the head of the zip tie can pass through it easily. Here's my pic of my finished bracket and also the pic with the ink pen pointing to the holes i made.
Now what you want to do is get yourself some zip ties that are at least 8 inches long, preferably longer. You will want to take your finger and poke a hole in the foam until you can feel the seat bar in each corner of your cutout. You will need to poke a hole on either side of the bar in each corner and fish a ziptie through the holes and behind the seat bar in each corner. make sure not to let the ziptie get twisted. For me this was the hardest part of the head rest install. Just keep working your finger and get the foam to pull away from the seat bar and you will eventually be able to fish your ziptie through. The good thing is the foam is pretty good about going back in to place. Don't hesititate to pull a big chunk back to get your fingers in there, just make sure you don't rip it all the way out and it will go right back when you're done. Leave the zipties poking out about halfway in each side.
Get your bracket in place and get each zip tie started but not tightened down. The longer zip ties you use, the easier this part will be. Make sure you have ran your cable for your monitor through the bracket and out the bottom of the head rest along the bar. You will then want to start cranking down the zip ties, a little at a time in each corner until you get the angle and depression into the headrest that you want. Keep in mind the seat bar is closer to the back of the seat the lower it goes, so at the bottom of the headrest you will want to get those lined up first. Pull in the top ones until the bracket is just where you want it.
Once you have the bracket in just the right place, cut the excess of the ziptie off close to the head and push the head into the holes we drilled. This way the screen can snap into place without being obstructed by the zip ties.
Now you just pop your monitor into the bracket and you're ready to tackle the rest of the install.
This is probably as far as i'm going to get until this weekend. I'm going to try and do the rest of the install this weekend which means stripping the cab down to the metal and dynamat'ing, running cables, headunit, etc. If anyone has any questions so far let me know!