Hey Radar,
From what I understand from talking with my flatmates who are both experienced riders, leaning off is basically that you sit right off the bike and lean your body right over into the direction of the corner you are taking. Your knee should be sticking out and your toes should be on the pegs and if you get the bike leant over far enough your knee should hit the ground, hence the term "knee down". I didn't have my toes on the pegs the other day and my boot scraped the ground before my knee, which is not desirable!
From what I gather you are to take the corner more with your body than the bike, you want to keep the bike as upright as possible and let your body weight do most of the work. The bike will always be leant over to a degree of course but it should be your body doing the bulk of the leaning.
Hope this helps and to all the experienced riders out there if I am wrong please feel free to correct me as I'm still learning too and want to soak up as much info as possible.
Cheers!

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