Lean back. It’ll be scary, but you have to go for it to successfully learn this trick. When your feet move forward to push the wheel, you have to compensate by letting your body move in the opposite direction (backward). You’ll know you’re making progress when you fall off backward. You may have to deal the wind getting knocked out of you once or twice 
I disagree. I think that the lean back comment is a mistranslation of “lean back further than you are used to”. Unless you want to learn backwards wheel walking, you do not want to lean back! You will put your weight slightly forwards of the wheel so you start falling forwards (hardly) and when you push (not kick) the wheel with your foot it will bring you into a nearly upright position so you constantly lean slightly forwards and keep pushing the wheel to catch you. It is a similar concept to riding except you are using your feet on the tire as a drive mechanism.
Sure- your upper body is slightly back to compensate for the massive weight of your legs out the front, but I think don’t overemphasise the lean back thingy. It’s all about making small corrections. When you fall off the back it means you need to lean forwards a bit more and maybe make better contact with your feet (they can slip if you dont push firmly). When you fall off the front perhaps lean forwards a bit less and maybe push a bit more with your feet to get the wheel underneath you. If you suffer from extreme speed buildup then perhaps focus on that lean back mantra so that you can take your time and place your feet carefully and maintain balance.
Practise enough against a wall to feel confident in the foot motion, but then break free into the open and repeatedly try and fail until you get the feeling of balance corrections- much like learning to ride except you probably have already learned how to ride with the pedals and it can be tempting not to practise since it’s so much easier to ride with pedals.
I think the term “kicking” the wheel more accurately describes the motion used in one footed wheel-walking where you give an extra hard push with your foot to make up for the dragging/gliding motion in between strokes.
Well, obviously one wouldn’t want to lean back so far as to do a backward wheel walk. I think you know I didn’t mean that. However, I do think leaning back past the point of balance for forward wheel walking helps you learn the correct balance point faster than just trying to lean 0.12789 degrees further back than the last time you fell forward. But not only that, when I started to lean back to the point where I might fall backward, I started to learn how to correct balance issues as well; to vary the speed of the wheel (in this case, to stop the wheel and let my body catch up, then continue); and what was a big plus for me in the end.
For me, holding onto a wall didn’t help much. It was good right at the beginning for learning how the foot motion works, but I didn’t really start improving until I was willing to just go for it and practice for huge chunks of time. Maybe the wall helps some people more than it helped me.
I have found the solution to my ww delema! Wear Water shoes, they are so flexible that it’s like normal walking!
If you’re not sure what water shoes are here is a pic.
