The cast: Preferably performed by a small group of bold young men. Backup crew includes a sound artist/radio operator, a hollywood-class makeup artist, a costume designer, and a driver for the getaway van.
For each member of the platoon: Assemble an authentic uniform as worn by a marine in the Vietnam war. Then the makeup artist goes to work on the men. Put a bullet hole in the head, amputate an arm, blow a gaping hole in the chest, cover them with dirt and blood, intestines spilling out, etc. The wounds should be very gory, disturbing and realistic. Get the soldiers geared up and into character: They are a group of fallen soldiers from the war in Vietnam. Authenticity is paramount. The uniforms, the equipment, everything should appear totally authentic.
Now is the time for the platoon to report for duty at a local military recruiting office. The approach should be slow and serious. This group of dead soldiers should seem lost and confused, as if transported directly from the battle of their death. They should avoid any direct confrontation with with the recruiting officer or other personnel at the recruiting office. Just act completely bewildered.
The tricky part is the escape. The performance here is key. A call should come through on an authentic vintage military radio carried by one of the soldiers. It should be a frantic call to action with yelling, gunfire and explosions, triggering the group to switch into battle mode with the leader shouting commands as the soldiers file out of the building following battle procedures.
The group should disappear as quickly as possible, making their way out of the sight of the recruiting personnel, staying in character all the way to the getaway van parked around the corner or in a back alley.