Into the Pit
The mission's starting point is along the projected path of the target. If you have unlocked the skill to blow up steam pipes, then you can use that to neutralize the convoy. Take out any remaining enemies or escape them.
Juggernaut
The target's route is short and will be in a distance away from your starting location. Quickly find a fast vehicle and head to the end of his route. There should be a steam pipe that you can trigger here, as long as you have unlocked the skill. Otherwise, you have to set up an ambush and finish him there. The target is riding a concrete mixer so you have to have some heavy firepower with you. IEDs and grenade launchers are your best options here.