Install;
1.Run OPENIV
2.Enable edit mode on the right side of the address bar
3.Once enabled navigate to update/update.rpf/common/data/ai
4.Find the Weapons.meta file
5.Once found click on it once then replace it with the mod
file.

tip: you can use the replace tool at the top of the tab
underneath the address bar, then navigate to the mod file, if
you can't find the folder it's because you need to extract the winrar or 7zip folder. 