Go to an area where there is only one soldier (such as the Strut E heliport). Shoot the soldier with the tranquilizer. Next, shoot him with the SOCOM gun in the arm. Take out your tranquilizer and shoot his radio so he cannot use it. Wake him up by spraying him with Coolant. When he wakes up, run and hide somewhere for a couple seconds. After that, run in front of him. He will be alerted and try to radio in. After two attempts to radio in, he will run to find another comrade to help.
Hold up a guard. After that, shoot him in the arm, the leg, then his radio. Stand in front of him and disarm you weapon. He will attempt to call for help, then helplessly limp away.