Sorry for the late reply to this, been busy with a bunch of things.
Long post coming.....
Normally, after 40 channels, the split point would be at the centre section. Once you add in more channels, extended patch bays and the optional producer rack the split point can be off by 16 channels. Here is what the split point looks like (find the attached image). It should stand out, but again I've seen this as far over as being between channels 8 - 9. On the last two 56 channel consoles I split, both with right handed patch bays, the split point was between channels 16 - 17.
Before you split the console, remove the panels on the bottom and back, channel strips, faders and meters, bumper and trim. Get some cups, keep all screws in order. Use the proper screw driver. If you need to remove the legs, you can do it the slow way with a wrench for those back bolts or remove the frame from the beams at the end and pull the legs.
You will have to cut a lot of zip ties.
To split the console is fairly simple. First, find the split point
. Next, from the split point to your patch bay - everything stays. Lets say your split point is between channel 16 and 17. You will need to go under the console to where the black BICC connectors are (these run from the patch bay to the channels). Make sure each cable has clear labels as they can fade or wear off easy. If the labels are not clear, the location for each is written on the channel PCB where they are plugged in. Just label every wire for the 16 channels (in this example) before moving on. Next disconnect the bicc connectors and pull them out the back of the console.
Next remove the ribbon cables that run to each bucket of 8 channels, they should be labeled already and they are cut to length so no worries. Pull them out the back.
Next pull the ribbon cables that jump between the PCB's at the split point.
Next you need to remove the ground rod. Most larger consoles will also have a split point for the grounding rods. They are normally around the centre section. Remove the two screws at the split point for the rods. You must also remove the bolts along the grounding bar on the side you want to remove. The bolts hold a thick ground wire to each PCB. You will have one on each rod (2 rods) every 8 channels minimum. Remove the bolts, leave the wires hanging, pull out the 2 bars. For each bucket of 8 channels you will also find the ground bar's being held up by grey plastic blocks. You don't have to remove those, just loosen the screws if needed. Note, as I said before you may be lucky and the grounding split point is with the frame split point. If that is the case, no need to remove the bars, just split them and move on.
Misc wires - You may have other cables running to the producer bay (even if you don't have one). Maybe it was removed at some point or someone wanted to add one. You may find a plasma meter power cable or the SSL headphone 2U connector. Regardless of what you find, make notes of it and pull those cables out the back of the console.
Next you need to pull all the meter cables and get them out of the way. Normally those go with the BICC's when you pull those.
Nearing the end - at the split point you will find a number of stitching screws that run all around the frame, these hold the frame together at the split point. I don't recall exactly how many there are but you must get them all. Even one left behind will be enough to hold the frame together and make for a bad day for you. They are easy to strip, use the right driver and no power tools here.
Next you need to remove the 4 bolts (2 pairs of 2 bolts) at the bottom front and bottom rear of the frame at the split point. When you pull the stitching screws you will see these. They should be there but I have seen several consoles where they were missing. These bolts are also used at several points across the console to hold black L shaped brackets that attach the frame to the black support beams.
At this point you shouldn't have any cables crossing the split point, double check all the way around. All screws should be out. The only thing holding your console together is the support beams.
The last step is to flip the console onto it's back. Some tip the console onto dollies, some strap the dollies to the back then tip. I usually don't need to strap them down. Make sure there are no back plates on the console where your dollies are.
Remove the two bolts from the beams front and back. The console should split without much effort. It may require a good first jolt as it's been sitting for a long time. If it splits a little and gets stuck, stop and check for screws you missed. If it splits a few inches and gets stuck - check the ground rod (some consoles have the ground rod split point right at the consoles split point, make sure both rods are split or removed). Check for cables that you missed, they should be easy to see at this point.
If you need to remove the legs, this is the time.
All done, move your console into place.
When putting it back together you follow the same steps in reverse. The only advice I can give is when it comes to the alignment of the frame at the split point. The 4 beam bolts go back first and can be tightened. Flip the console. The 4 bolts for the frame shouldn't be locked down, you may have trouble putting them in at this point. Every stitching screw all the way around should line up and go back without any issues. If one won't line up or goes in on an angle, many more after will get worse and worse. Start in a easy spot and add the stitching screws but don't tighten them. This allows you to move the frame a little to get it just right. Once all the stitching screws are in, those 4 frame blots should just pop in without any problem. Tighten them all down and move onto the easy stuff.
If you should forget exactly how the cables go back, just look at the other side of the console and follow it. Add in new zip ties as you go across the back.
All done.
