Installation:
Replace the files in:
mods/update/x64/dlcpacks/patchday8ng/dlc.rpf/x64/models/cdimages/weapons.rpf
mods/update/x64/dlcpacks/patchday3ng/dlc.rpf/x64/models/cdimages/weapons.rpf
mods/update/x64/dlcpacks/patchday2ng/dlc.rpf/x64/models/cdimages/weapons.rpf
(Make sure to back up your files!)
Credits:
batman78