Hiya, and welcome to BYC!
I can only reiterate those above, 1/2" hardware cloth is your answer. Solar motion lights as well help us immensly.
You may find more ideas in this forum, or you can post in it.
https://www.backyardchickens.com/forums/predators-and-pests.13/
If you want some remodeling ideas, here's another forum where folks will help you: https://www.backyardchickens.com/forums/coop-run-design-construction-maintenance.9/

I can only reiterate those above, 1/2" hardware cloth is your answer. Solar motion lights as well help us immensly.
You may find more ideas in this forum, or you can post in it.
https://www.backyardchickens.com/forums/predators-and-pests.13/
If you want some remodeling ideas, here's another forum where folks will help you: https://www.backyardchickens.com/forums/coop-run-design-construction-maintenance.9/