If you are using a modern browser, you can play the video back at a slower rate - click the gear icon (you have to be using the HTML5 player, not the flash player).
That being said - the instructions for cabling left a little bit to be desired, this is what I recall doing. Some of this is based off looking at the pictures (ie, the instructions don’t say how to route the motor wires, but the pictures show that the connectors are routed through the chain):
-Note: both cable chains are the same length, but you will need to remove some segments from the Y-axis when you do the steps for the YL cable-
Create labels for all cables - two for each gray motor cable (X, Z, YL, YR), and one for each homing cable (X, Z, YR).
---- Z & X ----
Measure the cables to find the Z and X cables, those two are identical in length, and the longest. Apply labels at both ends, and at the ends of the homing switch ends.
Remove all of the cable chain snaps - I could not route the cable ends through the closed cable chain
Lay the chain in position
Attach the chain to the bracket
Take the wires from the steppers and run them into the chain
Attach the motor wires to the steppers
Route the X, Z motor and limit switch cables through the chain
Place a few snaps along the length so that the wires don’t fall out
At this point you can snap all the cable chain pieces on
Finish by attaching the chain with the tape per instructions (I wish they had provided holes for screws)
---- YR ----
YR’s cable is shorter than the X, but longer than the YL cable. Apply labels at both ends, and a label to the YR homing cable.
Stretch the stepper cable so that it is taught, but not stressed along the back of the X gantry rail. Use one of the sticky-backed zip-tie plates to hold it on. Don’t cinch the zip-tie up yet.
Stretch the homing switch alongside the stepper motor, tying it up along with the YR motor cable.
---- YL ----
Apply labels to remaining motor wire
Remove suggested # of segments from the cable chain.
Remove all of the snaps from the remaining chain
Attach plate for the cable chain - I had to remove two screws from the stepper, and replace them with the longer ones provided. Once done you can add the plate and bolt it on.
YL - as with the X and Z cables, rote the motor wire through the cable chain then attach the motor wire at the end.
Lay YL cable through the cutout in the YL gantry plate, then YR, then remaining.
For the cable chain, route YL wires first, then YR (both motor and homing), then the wires coming from the other cable chain
I zip tied my cables together between the cable chains
Stick the cable chain to the YL rail
That should be it - but I can try and answer any questions. This isn’t official, of course Some of these steps I had to interpret from the photos and written instructions. There is a Shapeoko Wiki out there that might talk a bit about cable management. And FYI - I didn’t feel comfortable running the motor connectors in the cable chain, but the pictures showed them that way, so I’m assuming that is an acceptable installation method.