Be sure to check the Filter out trucks from your Warzone. In this way you are avoiding to accidentally loot trucks from our own server.
Choose the truck that you want to loot. Check which server we are up against and choose the right one. Or just choose any truck you like and click on Plunder!
Next screen brings you the option to attack the truck you selected, or if you want to find secret tasks on that server, click on the map and search for suitable tasks. Remember: the best one's are yellow and purple.