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！