Center all your trims (except throttle. all the way down like you have it). Once your trims are centered on your TX, now power it up, your servo arms "must" be at 90*. If you must, position the servo arm more to the "upward" rather than "downward." Support the servo arm with your thumb or finger from moving while you remove the screw. Then manually try to level the swash with the pushrods.
BTW, That is NOT my write up on the tutorial. I think it's some nice guy called "Klondike"