The instructions for HotKeyNet are available on the HKN website http://www.hotkeynet.com/p/doc1.html
You can keep going Next at the bottom of each page to go through the manual.

But, essentially, once you have HKN installed with the server/client configured, the script file is pretty much the same regardless of whether you use one computer or multiple. The only difference, is when multiple computers are available is you can add an extra filtering element in your config to send commands to a specific computer.

There are plenty of samples and instructions in the manual.