I've seen that people use "how easy is it to […]?" and "how easy is to […]?"
Another example could be:
I couldn’t ignore the barrage of research showing how easy it is to screw up your kids.
Could it be written as follows?
I couldn’t ignore the barrage of research showing how easy is to screw up your kids.
Admittedly, it sounds much better the first form, however, is there any rule regarding the use of it's versus is.