I can't tell you how since I never played earth main. Did you check youtube though? I found a lot of helpful videos there. Just make sure they are not so old or at least they are from 4.0. If you don't find videos for earth main, change to other mains. For some ninja exams certain mains would work better than others.

i did , all of them were in version 2.0 and use asuma wind blade with 8 gates lee , i switched to water and fire main but i didnt do it with those either

Try this. This is what I used:

https://www.youtube.com/watch?v=-nDv9P2OgEM

Ill try that tommorow since i already changed mains , thanks :D