How is one of those interrogative words that lets us ask a question, often with the auxiliary verb do:
How do we communicate?
How asks about the manner of something (here, communicating). By dropping the do, we can transform this question into a clause that stands for the manner of that something:
how we communicate
Manner is an abstract noun, and wherever we can use that noun in a sentence, we should be able to use the how clause in its place:
As the subject of a sentence:
The manner of our communication is important.
How we communicate is important.
As the object of a transitive verb:
I like the manner in which we communicate with each other.
I like how we communicate with each other.
As an objective complement:
He showed us the proper manner of communication.
He showed us how to communicate properly.
And, as in your sentence, as the object of a preposition:
The change is in the manner of our communication with each other.
The change is in how we communicate with each other.
The appearance of a particular preposition doesn't depend on the how clause, but rather on what word licenses that preposition, i.e., what preposition is idiomatic with the word. Change can take in. Talk, on the other hand, takes about. So it's no surprise that we say
Change in how we communicate.
Talk about how we communicate.