The beat the song is built on is one bar, played through bars 5-23, 25-27 and 29-31, and 1 more place -- 28% of every bar the kit plays. That is the spine of it; everything else is what happens around it.
It is played on ride, snare, kick and hi-hat foot, counted in thirty-second notes. On its own it scores 15 out of 100 -- straightforward -- and the thing that decides that is how fine the subdivision is.
The whole song is 71 out of 100, so the beat is not the hard part: what costs you is everything around it, the joins and the fills.
There is not much to reduce here -- the room opens it near enough as written, at 40 BPM, and asks for it clean before it moves.
Two tempos only, 40 BPM, and the gate at each is 8 loops in a row with no wrong note and no wobble in the time.
PRACTISE THIS BEAT →A one-bar groove on ride, snare, kick and hi-hat foot, in 3/4 at 40 BPM, counted in thirty-second notes. It is written out above, and it covers 28% of the bars the kit plays.
Bars 5-23, 25-27, 29-31 and 58-65. The time is kept on the silence to start with, and it changes 5 times over the song.
15 out of 100 on its own -- straightforward. The song as a whole is 71 out of 100: demanding, mostly on the independence between the hands and the feet.