Just a side note: You should be able to install the knife by searching "knife" in the search button and then clicking "search all archives" in OpenIV. Scroll down until you find the w_me_knife_01.ydr and then replace it and the .ytd. I tested this model in FiveM, as it makes testing much faster, and because of that I'm not entirely sure where to install it. If someone finds a directory that works send me a comment and I'll post it in the description of the model!

@de_verett
Working fine thanks.
Mods/Update/x64/dlcpacks/patchday3ng/dlc.rpf/x64/models/cdimages/weapons.rpf