This trick basically feels like a shoulder dismount to me, except that instead of placing your shoulder on the pole, you're placing it on that bottom knee, if that makes sense? I put my hands one knee height, one thigh height, but I have seen people use different heights of hold.
The most important part of this trick for me is to make sure that I am actively pushing out with that bottom foot before I release the top knee... my bottom leg locks out into my torso before I start leaning forward to split. Again, basically like a shoulder dismount -- I'm locking my leg and making it into my pole lol. Straighten that leg completely, making sure to actively push with the foot and pull with the arms, then start bringing your top leg down.
I also find this trick a lot easier from the pole than from the floor. Just do it really low to the ground starting out and grab some cushions... it really isn't that scary to fall out of close to the floor, since you will fall on your back and not your neck or face lol. I took a couple tumbles learning to dismount from it.
It definitely does take a lot of balance and control, but again, I find it easier from the pole than the floor. Also, if you have sweaty feet, make sure you wipe down the pole and your feet well, and use grip aid on your feet when learning if necessary.