The basics of this are relatively straightforward:
The switches on the GiO transmit MIDI CC messages (and "listen" to these messages too, which is handy for visual feedback regarding what is switched on etc)
In MS, one can create Screen Control buttons. These can be mapped to most parameters with MS, and they can be assigned to in-coming MIDI messages from the GiO.
(Note, it is also possible to Assign and Map without Screen Controls in MS 2.2)
So, starting from an empty Concert
Create your Patch, with Channel Strips and plugins as required.
Create the Screen Controls for the Switches in Layout Mode. Select each one in turn, and "MIDI Learn" to the incoming MIDI by pressing the Assign button and operating the switch 3 times. If you want, select The GiO in the "Send Value to" parameter, so that the GiO switch lights up when it should. Turn off "Assign".
In Edit Mode, you now need to map the Screen Buttons to particular parameters for that particular patch (say for example, to bypass a Stomp Box in the PedalBoard plugin):
Several ways to do this, but the easiest is to select the Button, switch on the "Map Parameter" function and then operate the Stompbox switch with the Mouse/Trackpad. Turn off "Map Parameter".
There are more complicated things that you may want/need to do, but these are the basics.
It is generally quicker to start with one of the premade templates, but these do use some additional 'features'.