I had a couple notes regarding the process..
Disassembling the bird-brain isn't necessary to complete this process. You can if you want to, but for the quickest bird --> personal recovery.. removing the 4 side screws holding the handebar together (see pics) and then removing the brain, in tact, then replacing with the linked dashboard is the quickest method, that i've found.
These are the screws that you need to remove to disconnect the handlebars..
Once the handlebars are disconnected, you can unscrew the cover plate screws, disconnect the headlight, then remove the other 2 screws holding the bird brain \ dashboard in place.
From there you can install your own dash and go on your way!!
Other side note, I've found that sometimes you are asked to do a firmware upgrade when you connect to the bluetooth... In my experience .. the firmware update limits the speed of the es2\es4 to 12\13 MPH... However, NOT upgrading does not allow for the scooter to be turned off via the power button nor does it allow for any function of the headlight.
Typically, you can click the power button once and the headlight comes on, click it again and the headlight turns off.. I may be wrong and my experience may be isolated, but I just experienced this by not upgrading the firmware.. The scooter is just permanently ON, with the flashing lights below the deck and the power button essentially does nothing. You cant control the headlight or turn the scooter off. On my other scooter, I did the upgrade and holding the power button in turns the scooter off.. tapping the power button once turns the headlight on or off, but limits the speed to 12\13mph.
Just my 2 cents!
Thanks so so much to @humanbeing21 for the original hack and for getting this all started!! ALL praise goes to him!!
Thanks all.