How do I upload my own card images?

I want to fix the blank card thing in my modules. I own the cards, etc.

Where are the blank card images installed? I’ll replace them with my own scans.

What I’ve done in the past when doing this for a few modules I extracted the vmod file like a zip file with 7-Zip and then there was an images folder in there, replaced the images in that folder with the ones I scanned and then made a new zip file with all the contents with 7-Zip again and renamed it to a .vmod file.