How to modify and add new feature into a minecraft rig?

So I wanted to make my own rig for animation, with the features I want. But I don’t know how to make rigs. So instead, I want to modify an existing rig to fit my needs. I’m using the PixelPerfect v1.5 rig by Pixel frosty to do just that. But I don’t know what to do now. As I mentioned earlier, I don’t know anything about rigs. I don’t know how am I going to modify this rig and add the feature I want. I do manage to Edit some part of the rig, but that’s it. What I want to know is how to make controls like this.


I do have some plans about what I going to add to the rig. Here’s what I’m planning for.

I want to add a switch called the second layer switch to enable/disable each part of the second layer in the render. I also want to modify the existing switch into an extrude switch. Also, I’m planning to add a switch to enable/disable teeth because the rig doesn’t have this feature.
Also, I have a plan to add more control to the face.

That’s my plan. I hope I can learn more so I can make this rig. And even hopefully in the future, I can make my own rig, not just Minecraft one. I hope someone can help me to learn more about Animation and how to make it. Until then, hopefully I could make this rig.