Those are good detailed instructions (though I don't see what 16,17 are for), so maybe further explanation isn't needed. But there are a couple simple facts (missing from the OFA documentation) that you should understand in order be able to get to instructions like these on your own from the basics of programing an OFA remote:

1) When you change setup codes for a device button (steps 2-4 and steps 13-15), it doesn't affect the rest of any previous programming for that device key (keymoves in this case, and learned signals on models that support those). So in Step 13-15 you aren't disturbing the keymoves created in steps 5-11.

2) When you create a keymove (steps 5-11), it does not store the device button of the source (step 7). Instead it stores the setup code previously programmed to that device button. If you later change which setup code is programmed to that device button, that has no effect on the setup code already stored in the keymove.