How to change packets in the local network?

Question

Windows

There are: 2 windows 8.1 computers (both), connected to the same router (wi-fi), it is also possible to redirect the connection through one of them.
Task: You need to change the traffic so that you can view and change data on 1 of them, which will then go to 2.
For example: On the 2nd computer, the chrome browser is open, the user requests a page and it contains the text "And this in turn.. ." or "Each of us ..." - it doesn't matter either.
But first, the page should come to the 1st computer, and there I could edit it
<text>И это в свою очередь...</text>
on
<text>Это означает что...</text>
and send this data to the 2nd computer. So that chrome does not suspect anything. - no matter what program from browsers to online games

Answer 1

no matter what program from browsers to online games

This is done very simply - you need to buy some kind of DPI (Deep packet inspection) system and configure it.

Answer 2

It is necessary to install a proxy server on 1 computer with the ability to filter and replace traffic by a dictionary (if there are none, then write your own based on some caching proxy), and on 2 computers, specify that the Internet is available ONLY through the COMPUTER1 proxy server.

Answer 3

Or use something like droidsheep

Answer 4

I'm afraid your problem is fundamentally not solvable with reasonable costs.
It is relatively easy to solve only for HTTP, with a stretch for HTTPS.