You don't need the cable and the software is free.

I've given rough descriptions of the process a few times in this forum.

Since that involves downloading the program IrToWav and nothing else here requires that program, I suspect a forum search for "IrToWav" would find most of those discussions and not much else. But I haven't tried that search to make sure.

You also can probably find discussions of DecodeCCF here (which you need if starting from a CCF rather than from an existing JP1 upgrade).

You also need the basic JP1 help files and probably you should use the RemoteMaster program instead of KM. There is a document for RemoteMaster that effectively replaces the KM specific parts of the JP1 documentation. All of that should be pretty easy to find in the JP1 forum.
[Link: hifi-remote.com]

There really ought to be a single document to walk a non JP1 user all the way through the .wav process, but I don't have time to write it.