He imagines having not having an experience there in the movie theatre, but watching a movie of himself having the experience. Furthermore, the movie should be silent, in black and white, and perhaps grainy, jerky, and flickering. As Carol Anne suggests, one can also have the subject supply an incongruous musical accompaniment. In other words, he imagines himself actually being there, seeing everything three dimensionally and in color through his own eyes as a participant. Like a VCR backspacing.
Speed is essential here.
This approach requires only a single session with the subject. Or at least so NLP claims, and my own experience confirms. The process itself usually takes less than fifteen minutes. When neutralizing a memory, the subject does not need to actually tell the therapist the details of the traumatic event. I take this as in indication that the process has not been completely successful.