New "Back to the Future" Set Shows Original Marty McFly

NEW YORK (CBS) It might be hard to imagine anyone besides Michael J. Fox playing Marty McFly in "Back to the Future," but another actor originally had the now-iconic role.

Fans of the film can see the original Marty - actor Eric Stolz - in footage that's part of the extras package in the "Back to the Future: 25th Anniversary Trilogy" set, which will be released on Blu-Ray on Oct. 26.

Pictures: Michael J. Fox

[Watch the video below.]

Details on the switch, which happened five weeks into shooting the film, are also provided in the extras. Part of the clip was posted on The Hollywood Reporter Tuesday.

Director and co-writer Robert Zemeckis said the casting change was "this horrific decision; it was heartbreaking for everybody."

Executive producer Steven Spielberg said that Zemeckis consulted him before pursuing the switch.

"(Zemeckis) showed me the first five weeks of shooting that he had put together," Spielberg said. "And he said, 'I just don't think we're getting the laughs I was hoping we would get.'"

Spielberg said he realized Zemeckis "was absolutely correct."

The decision changed pop culture history. Zemeckis was able to "convince the studio to let me reshoot five weeks of work," and Fox was cast in the career-defining role.

The original "Back to the Future" was released on Oct. 26, 1985, went on to gross $381 million worldwide and lead to two sequels.