Don't know about those stem and bars, but you want high and short I think.
It's another one of those moves you just need to practise. I found it helped to think of moving back instead of just trying to lift the front.
Harder to learn manuals with a good brake, really helps to feather it for adjustments, took me ages to learn doing them when I got a back brake that worked like it was supposed to.
And you got to relax and be loose, make sure your moving your body to adjust balance