"It's really simple."
     It's  a piece of cake.
     It's easy as pie.
     It's easy as ABC.
    It's no big deal.
    It's a no-brainer.
   I can do it with my eyes closed.
   That's no sweat at all.
   Nothing to it!
   It's a joke.Anyone can do it.
  It's a cinch.

1. It's really simple. / It's very easy.
很简单。

2. It's a piece of cake.
小事一桩。

3. It's easy as pie. / It's easy as ABC.
真是易如反掌。

4. It's no big deal!
没什么大不了的！（很简单）

5. It's a no-brainer!
这很简单，不用花什么脑筋的！

6. I can do it with my eyes closed!
我眼睛闭起来都能做！

7. That's no sweat at all!
那一点都不难！

8. Nothing to it!
没什么难的！

9. It's a joke. Anyone can do it.
这很简单。谁都可以做。

10. It's a cinch!
简单的很！

good

It's nothing,也可以归类吧

挺好的小结