those unaccustomed to waking up early"

[Vladv1]

"Here is an advice for those unaccustomed to waking up early" Is the part in bold grammatically correct in my own sentence?

 

[jutfrank]

Yes.

Change 'an' to 'some' and you have a good sentence.

 

[emsr2d2]

Alternatively, you could change it to "a piece of advice". Also, you need a full stop after "early".