How could a person make it so that everything else is in slow motion
The faster you travel, the more time slows down. So, if you could travel closer to the speed of light, time and relative motion will slow down. Light travels at 186,000 miles per second. The hard part is how to do it.
Perhaps use their imagination... lol
Film it in slow motion; the film runs faster when you're filming, so when you view the film as "regular" speed everything looks slow.