For SkylineGTRFreak's FA-18E   
https://www.gta5-mods.com/vehicles/uh-60-black-hawk-mega-pack-add-on-vehfuncs-v-tuning-lod


Once installed with their instructions, open the dlc.rpf with OpenIV

Follow this path to the file to overwrite:

...\GTAV\mods\update\x64\dlcpacks\helicopters\dlc.rpf\x64\levels\gta5\vehicles\helicoptersvehicles.rpf\uh60l.ytd

If you wish to retain the original livery pack, while in OpenIV, extract the file uh60l1.ytd.  I typically extract the original .ytd to the same folder as the dlc.rpf and rename it to origuh60l.ytd.

When ready to overwrite with one of the provided liveries, toggle "Edit mode", top right button, and drag uh60l.ytd from the extracted zip file and drop here: 

...\GTAV\mods\update\x64\dlcpacks\helicopters\dlc.rpf\x64\levels\gta5\vehicles\helicoptersvehicles.rpf\uh60l.ytd

Just to confirm the livery, I'd click on the uh60l.yft or uh60l_hi.yft file to open the OpenIV Model Viewer to see what the model will look like with the new livery.

Once satisfied, close the model viewer and run GTAV and spawn uh60l with the trainer of your choice.


Enjoy,
Gillman

