How do you teach roll up to an all levels class?

I teach an all levels mat class and I love roll up but I know it’s quite difficult for folks. Some people in my classes get it right away and for others they cant get up at all. I recently started teaching with knees bent, feet flat hands on the back of the legs and rolling down then rolling up and offering people to grab onto the backs of their legs to help them up then legs go long but I am not sure if this is helping or hindering.

I am wondering how others teach it and do I just let people struggle as they build the strength?? Or is this too tricky of an exercise to teach in an all levels class?