Peter Lenkov, executive producer of the “Hawaii Five-0” reboot, always believed the pilot episode of the original series felt like a movie that belonged on the big screen.

It’s finally happening, in a way.

Fifty years after the original “Five-0” first aired on television, a modern-day re-creation of that pilot, also called “Cocoon,” will debut on a big screen, at Sunset on the Beach Sunday in Waikiki. Fans of both the original and new series have the chance to see it, along with the premiere of the new version of “Magnum P.I.,” also produced by Lenkov.

With “Cocoon,” the new “Hawaii Five-0” honors the 50th anniversary of the 1968 premiere of the original show.

The show’s star, Alex O’Loughlin, who plays Steve McGarrett, said the modern version of “Cocoon” — like the original pilot — has a different feel than other “Five-0” episodes.

“It was a little far out,” O’Loughlin said. “There are interesting costumes and sets and weirdness.”

But O’Loughlin appreciates Lenkov’s ongoing homage to “Five-0’s” roots.

“It is not lost on me what an honor it is to be part of something with a lineage that ‘Five-0’ has,” O’Loughlin said. “It’s a big deal. … When I get a chance to reflect on the fact that this is going on 50 years, it’s not lost on me how rare that is.”

The new version begins its ninth season with actors such as O’Loughlin portraying characters from the original series, along with veterans such as Dennis Chun and Al Harrington, who appeared in both versions.

“Fifty years, that’s hard to believe,” said Harrington, 82, who played Honolulu police Det. Ben Kokua in the original series and is now featured in the reboot as surf shop owner Mamo Kahike.

Harrington called Lenkov’s remaking of the original “Cocoon” “proper respect.”

“It’s respect to the character of the show Leonard Freeman created,” Harrington said. “He had such aloha for Hawaii and its people. For us who live here, it’s the Hawaiian style, the aloha spirit.”

Lenkov’s version of “Cocoon” is hardly a scene-by-scene re-creation.

Instead it offers plenty of storytelling challenges for a series that has to resolve issues from last season, while explaining how Steve McGarrett’s nemesis in both shows, Wo Fat, reappears (his death took place in the 100th episode of the reboot in 2014).

Actor Mark Dacascos, who portrays Wo Fat, tweeted a link to an article on Wo Fat’s return. On Aug. 30, Lenkov retweeted the post, commenting: “We’re blowing minds, Mark … no one can figure out how Wo Fat comes back to life. Folks attending Sunset on the Beach will find out first. #h50”

Lenkov told the Honolulu Star-Advertiser that in the new version of “ ‘Cocoon,’ I have to acknowledge there were storylines set up in motion in Season 8 that I have to pay off. It’s definitely not scene-by-scene, but it’s faithful to the story. I wanted to do something very special for the 50th anniversary. The way to make it was to retell the pilot of that show. The original pilot of ‘Five-0’ was very much like a movie in the age of ‘Dr. No.’ You could feel there was sort of a big idea there that felt more for the big screen than the small screen.”

Asked specifically about how the new version of “Cocoon” will accommodate Wo Fat, Lenkov played coy.

“He’s very, very dead, but he’s alive in our version of ‘Cocoon.’ I know it doesn’t make sense, but it will the minute you see him on screen.”

Lenkov said he fell in love with the original “Five-0” as “a very little boy growing up in Montreal, Canada, as far away from the beach as you can get. That show warmed us up during the winter and you would feel like you were on vacation every week. That’s why it was my dad’s favorite show.”

Lenkov called the rebooted series “really a valentine to the original. We honor that show that Leonard Freeman created and we acknowledge the fact that we are standing on its shoulders and could not do this show without that foundation.”

As for the future, speculation that this season could be the last, Lenkov said:

“They’ve been writing our obituaries for eight years. I never take any stock in that. Every season they say it’s our last season. Season 1 they were saying it’s our last season. If the audience tunes in, if they’re still watching the show and enjoying it with the same amount of passion … then we have a lot more life left in us.”

MEMORIES RUSH BACK

In the reboot, Chun, 67, portrays HPD Sgt. Duke Lukela.

Chun, in his early 20s at the time, played bit parts in the original. He was attending Chaminade University and was brought onto the set to work as an actual security guard by his father, legendary “Five-0” actor Kam Fong, who portrayed Det. Chin Ho Kelly.

“Dad wanted to keep an eye on me,” Chun said.

But the casting director liked Chun’s look and asked his dad if he should be on-screen as a gas-station attendant with one line.

“Dad said, ‘Only if he’s the best actor for the part,’ ” Chun remembered. “I was really angry. Dad said, ‘This is a tough business. You want to make it on your own.’ ”

Chun can’t remember his first line exactly, but he remembers the feedback.

“Dad said, ‘They said you didn’t ham it up,’ ” Chun recalled. “My father said, ‘You go there, you go to work. You don’t go to play.’ ”

Chun ended up playing five characters in the original series, but never got to act directly with his father. When he auditioned for the reboot to play a recurring character, he felt the presence of the original stars, Jack Lord and James MacArthur.

“All these memories came rushing back,” Chun said. “You expected to see Jack and Jimmy. You felt their support. They were all there and saying, ‘Go for it.’ ”

The new show paid tribute to Kam Fong by creating a character whose name blended Fong’s real and character names: Kam Tong Kelly.

And the Season 7 DVD includes an eight-minute feature on the Chun family that includes Dennis Chun’s roles on both shows.

“It was very touching and they did a real good job,” Chun said. Chun’s longtime partner, Laura Mello, has since played his on-screen wife in the show.

“It’s really touching how people love both the old and new shows,” Chun said. “They made 50 years possible.”