TC The Division Lincoln Tunnel 5th Mission Walkthrough 

Mission minimum required, Level 05. Difficulties, Normal.

First destination, Reach the security entrance. Watch out on the snipers.
Second Destination, Secure the Tunnel Entrance. Again theres two snipers on the roof. Kill all the hostile specially those who have icons.
Third Destination, Reach the Floodgate.  This is pretty easy, kill two hostile and your up on the next.
Fourth Destination, Protect JTF while the bomb is disarm. 3 mins to hold and protect. IF he dies, you have to start again this location. They include some boss in this fight.
Fifth Destination, Talk to Roy Benitez.
Sixth and final Destination, Protect Benitez. This fight is kind a hard if you go in in lower level. All kinds of hostile are here including boss.

To Complete the Mission, Go back to you base of Operation and talk to benitez. Once its compete, you will receive that you unlock the Wing Security including the mission.