Installation:

1: Install this mod:
https://www.gta5-mods.com/vehicles/mtl-tanker-add-on-template-ag_mods 

2: Extract the "tanker_sign_5.dds" file

3: Add it to the "mtanker2.ytd" and "mtanker2+hi.ytd" files in "C:\Program Files (x86)\Steam\steamapps\common\Grand Theft Auto V\update\x64\dlcpacks\mtanker2\dlc.rpf\x64\vehicles.rpf\"