Following his tour of sea duty, he was appointed a drill instructor at Marine Corps Recruit Depot San Diego.

Guillen was presented to his parents on his behalf by the Secretary of the Navy Charles S. Thomas, during a special ceremony in his office on August 18, 1954.

Participating in the defense of an outpost forward of the main line of resistance, Staff Sergeant GUILLEN maneuvered his platoon over unfamiliar terrain in the face of hostile fire and placed his men in fighting positions.

Although critically wounded during the course of the battle, Staff Sergeant Guillen refused medical aid and continued to direct his men throughout the remainder of the engagement until the enemy was defeated and thrown into disorderly retreat.

Succumbing to his wounds within a few hours, Staff Sergeant GUILLEN, by his outstanding courage and indomitable fighting spirit, was directly responsible for the success of his platoon in repelling a numerically superior enemy force.

His personal valor reflects the highest credit upon himself and enhances the finest traditions of the United States Naval Service.