The install instructions are right on the page where you add them to the cart or order them. For instance, read the info here on this page:
https://marketplace.reallusion.com/camera-auto-focusClick the SHOW DETAIL link
All of the plugins go into the same folder:
Copy Camera_Auto_Focus folder into the iClone install directory > ...\Bin64\OpenPlugin.
Just make sure each of your other plugins has its own main folder within the ...\Bin64\OpenPlugin folder.
Hope that helps,
schemer