Replace all icons in one library with icons from another library?

I am looking for the best was to swap icons in a design system library with icons from another library. basically I have a design system library with icons but I want to replace all those icons with newer icon set. The swap library only matched the same ones but the new icon library I have has many more new icons that are not in the original library.

Thought? Plug-ins?

Swap library to the rescue. Just make sure the naming and the layer structure are the same

What happens when the new library has icon that are not in the original? Are they brought over as well since there is technically nothing to swap them with?

Nothing happens. It is going to be there, available, nothing more. Library swap works over assets that are being in use