Here are the Usual Guidelines:
For each adult, standard-sized hen you need:
- 4 square feet in the coop (.37 square meters)
- 10 square feet in the run (.93 square meters),
- 1 linear foot of roost (.3 meters),
- 1/4 of a nest box,
- And 1 square foot (.09 square meters) of permanent, 24/7/365 ventilation, preferably located over the birds' heads when they're sitting on the roost.
After blowing up the photos it looks like the panels are held in a metal frame with some structural wood at the corners to hold the metal frames together, right?
If I'm seeing it correctly, you should be able to do this at the front, cutting out the area marked in blue and replacing it with hardware cloth:
View attachment 3128267
With a roof on the run you won't need to put an awning on it.
The back roof is so low to the roosts that you might have to just leave the existing vent, which is, at least, baffled so wind won't blow directly on the roosts.
Sandwiching the hardware cloth and the panel between trim boards is probably the most secure way of doing this.