For The GTAV Mirage III
Here https://www.gta5-hub.com/vehicles/70-fighter-and-sports-planes-add-on

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

Follow this path to the file to overwrite:

...GTAV\mods\update\x64\dlcpacks\ZF1\dlc.rpf\x64\levels\gta5\vehicles.rpf\dm3.ytd

If you wish to retain the original livery, while in OpenIV, extract the file dm3.ytd. I typically extract the original .ytd to the same folder as the dlc.rpf and rename it to orig_dm3.ytd.

When ready to overwrite, toggle "Edit mode", top right button, and drag dm3.ytd from the extracted zip file and drop here:

...GTAV/mods/update/x64/dlcpacks/dm3/dlc.rpf/x64/levels/gta5/vehicles.rpf/dm3.ytd

Just to confirm the livery, I'd click on the dm3.yft or dm3_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 dm3 with the trainer of your choice.


Enjoy,
Gillman