Two Tickets

Force Taggart Out into the Open

In order to force Taggart out into the open, you'll have to destroy the building he's currently residing in. The easiest way to do this is to steal one of the tanks (make sure to disguise yourself as a soldier first, so you don't drawn unwanted attention) around the base of the marked building and its weapons to lay into the structure (it doesn't matter where you hit the building). If your tank gets destroyed, hightail it out of there and lose your pursuers before going back for a second tank and doing the same.

Force Taggart to Flee

After destroying the building, Taggart will take off in his tank, stopping a total of three times where he'll be protected by several escort tanks which need to be destroyed. Make sure you keep up as he drives around the city, as you'll fail the mission if you fall too far behind. Once he comes to a stop, however, you'll have to take down the marked tanks protecting him, without damaging the tank Taggart's in. The easiest way to do this is look for a rocket-launching enemy nearby, consume him to gain his weapon, then target one of the tanks from a rooftop (without being watched) and fire all four rockets at it to destroy it. You'll then have to head out to find another rocket-launcher to target the next tank.

Each of the three locations has different places ideal to find rocket-launchers. At the first stopping point, check the nearby rooftops. At the second, look in the nearby parks. For the third, check the street near the tanks themselves. Ideally, you should try and stealth-consume them the soldiers if you can (you may have to follow them around a bit first), but normal-consuming will work too--just make sure to grab the dropped rocket launcher and hightail it out of there to switch disguises and get the military off your tail.

Consume Taggart

Once you've destroyed all the tanks at all three locations, chase after Taggart's tank and hijack it to consume him and complete the mission.