Day five now, ~25 days previously. I've just been keeping the total for the year down to 20 or so since I find that past day 30 or so things get unpleasant. Though with the physical changes I've been experiencing and with Corona-chan floating around, that may change. I'm taking care to guard my vitality every way I can, as Corona-chan does not fuck around.
>how
Practice and refinement over a few years. At first you think "I should try nofap", then discover that you have this habit of looking at porn every day at porn o'clock. So you make a point not to do that anymore, and it's good; you have fewer temptations. But you find that you still have temptations that arise not because of your "physical" habits, but because of mental habits, like idly fantasizing. When temptations appear by happenstance, you might inwardly indulge the sensuous tendency inculcated into all of us, which weakens your resolve as sure as if you had visited a porn site.
Learn to reject the "porn" that appears on the screen in your mind's eye.