If the non-drummer is a musician, I figure the simplest thing would be to write it out, no?
If the person, however, is NOT a musician by any stretch of the imagination, and cannot get him/herself to "feel" what the fill is about (no pun intended), then (IMHO) it would be utterly pointless to even attempt an explanation...
Fast forward to 1:06. This is the intro. It is a type of fill.
At 1:10 he starts the beat, which is the basic rhythm of the drum part.
At 1:16 he starts yet another fill, this one lasting until about 1:18, at which point he returns to the beat.
At 1:24 he starts a final fill that he uses to end the beat.
If you don't understand what a drum fill is now, I'm afraid you never will.