Slow Motion in music video but lyrics on synced?

[SunnyVisualz]

I knwo how to do slow motion, i shot in 60fps 720p with my t5i.. slow mo look great, i don't need to know how to do slo motion. I need to know how to ahiceve the look in the video "King Of The Fall - The Weeknd" I want slow mo but I want the lyrics to be synced.. Do I have to slow down the song? I'm stuck here. Thanks.

 

[bandcoach]

when shooting the video play the track back at double speed and have them mime to that double tempo - that way the lyrics come out slo-mo along with the video