Modifying Wynn Models and Weapons

Ok so, basically I've finished some models of katanas in Blockbench that I want to replace some default weapon models with. I have been advised to replace (instead of making a seperate pack entirely) the current weapon files with my ones but I'm not too sure how because when I open these files to see which one I need to replace, I keep getting this error.


(I had gotten a copy of the default Wynn pack by going into server-resource-packs and getting the latest one then renaming)

Even when I try to copy the files into a normal folder, it only gives me a fraction of the actual files I want which is followed by this same error. And when I also try to open the files that actually copied over I just get the file's name displayed on the picture app with no actual texture. If someone could give me a guide that'd be incredibly helpful, thanks!

 

I think olinus10 made a vid about modifying weapon models. Link: