They want to get down to well under half a billion as far as I can tell.  For the sake of argument lets say that 1 of 10 survive. Knocking off 9 of 10 people should be pretty easy.  Announce a 'covid-19 vaccine' tomorrow and you've got it.

The trouble is that unless a fair bit of effort is undertaken the 1 of 10 people who survive are going to be highly selected toward those who are resistant to the current threats.  That is to say, resistant to 'you' and your bullshit.  It's a natural fallout of the evolutionary principle.  Then instead of a sheep ratio of 99/100 you end up with a sheep ratio of, say 1/2 on a population-wide basis.  That's not a winning end-game for 'you'.

You are pretty much going to need (mis-labeled) 'AI' to decide who to bump off and who to keep and an individually selective system of doing the deed in order to ensure that you end up both with the overall population numbers you want AND the appropriate ratio of sheeple, potential sociopaths with skilz, general boot-lickers (aka, 'noahides'), etc.  A good working ratio is (((2700-to-one))) worker bees to chosen, but again, you gotta get the right 2700 from the current population or the experiment is an immediate fail...and hold that ratio steady or things won't be 'sustainable'.

'Social media' (Google, Facebook, Twitter, etc) have gathered the data needed to determine who are 'safe keepers'.  Now it's just a matter of 'pursing the seine' in such a way that the fewest of the unsafe ones get away.  Just like herring fishing in Alaska, it is common that the entire season comes down to one set.  Get it wrong and you have to wait until next year to try it again.