GE 45600 as a Secondary Controller

So, all my devices’ ID’s are less than 32.

I had looked over this thread in the past but still don’t know how to make the remote a secondary controller. Do I set it in SmartThings under device type? Is it a setting on the remote itself?

And then where do I associate the switches with the remote? Is that done through the remote and the switch or through the SmartThings hub web interface?