The beat the song is built on is one bar, played through bars 1-20, 22-44 and 46-60, and 1 more place -- 90% of every bar the kit plays. Learn that one and the song is very nearly finished.
It is played on hi-hat, snare, high tom, mid tom, floor tom, kick and hi-hat foot, counted in sixteenth notes. On its own it scores 50 out of 100 -- a step up -- and the thing that decides that is how much of it falls off the beat.
The whole song is 69 out of 100, so the beat is not the hard part: what costs you is everything around it, the joins and the fills.
A part this hard is not learned by playing it slowly and hoping. The room opens it on its simplest reduction -- the timekeeper alone, at 63 BPM -- and adds the notes back over 3 rungs, each with a tempo to reach and a gate to pass before the next.
Tempo goes 63, 74 and 84 BPM, and the gate at each one is 8 loops in a row with no wrong note and no wobble in the time.
PRACTISE THIS BEAT →A one-bar groove on hi-hat, snare, high tom, mid tom, floor tom, kick and hi-hat foot, in 4/4 at 84 BPM, counted in sixteenth notes. It is written out above, and it covers 90% of the bars the kit plays.
Bars 1-20, 22-44, 46-60 and 68-99.
50 out of 100 on its own -- a step up. The song as a whole is 69 out of 100: demanding, mostly on how much of it falls off the beat.