The beat the song is built on is one bar, played through bars 26-38, 42-48 and 51-65, and 5 more places -- 66.3% of every bar the kit plays. Learn that one and the song is very nearly finished.
It is played on hi-hat, snare and kick, counted in sixteenth notes. On its own it scores 71 out of 100 -- demanding -- and the thing that decides that is how many notes a second it asks for.
The whole song is 76 out of 100, so the beat is most of what the song asks for. Get it clean and the rest follows.
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 68 BPM -- and adds the notes back over 5 rungs, each with a tempo to reach and a gate to pass before the next.
Tempo goes 68, 82, 96, 110 and 124 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 and kick, in 2/4 at 124 BPM, counted in sixteenth notes. It is written out above, and it covers 66.3% of the bars the kit plays.
Bars 26-38, 42-48, 51-65 and 68-74, and 4 more places. The time is kept on the snare to start with, and it changes 5 times over the song.
71 out of 100 on its own -- demanding. The song as a whole is 76 out of 100: demanding, mostly on the independence between the hands and the feet.