no "transfer procedure" as such - just install Lightroom on the new machine and input the serial/licence number - that's it.
You're allowed by the terms of the licence to have Lightroom "live" on two machines at the same time (using only one at any given time), and - if (say) you've already got Lr on a laptop and are also moving to a new desktop PC, and you want to stick to the letter of the licence - it's a simple matter of uninstalling Lr from the PC that you're no longer using and installing it on the new desktop,.
Thank you Keith,
so there is no "deactivate" to do before uninstall, like PSE.
That's right, Alessandro - no deactivation.