Authorize the new machine through the site via your login, download, install all appropriate apps.
Then, you can De-Authorize the prior machine if desired.
I do recommend storing your user presets via the cloud, or Dropbox or whatever, that way, no matter which machine you happen to be on, it will pull from a centrally located library.
Application: I have 2 machines in 2 different cities, and I have all of my Pro Tools sessions as well as all related libraries in Dropbox, rather than having multiple redundant copies of the same functioning files/sessions/presets on multiple pieces of hardware. It also frees up storage on the hardware.
