别担心，就一步一步地处理事情。

Just take things ___step ___by ___step and don't worry.

这本书一步一步地指导你如何应对恐惧。

The book guides you ___step ___by ___step on how to cope with fear.

一步一步地按照指示来完成这个过程。

Follow the instructions ___step ___by ___step to complete the process.