Question

1. Do it like I tell you.

2. Do it as I tell you.
3. Do it the way I tell you.
4. Do it in the way I tell you.
[Can we use all the expressions? Are they all grammatical? Which ones are commonly used?]

Answer 1

2 - 4 are grammatically correct.

("like" should be followed by a word or phrase, but not a clause)