On MAC
the Negative Lab Pro installer will add them for you automatically to the standard location for Camera RAW profiles.
On Windows,
If you want to use the Vuescan RAW profiles, you need to add it yourself. You will want to copy the entire “Vuescan Profiles” directory to the default Lightroom location for camera profiles.
On a typical Lightroom install, the location will be C:\Users<YourUsernameHere>\AppData\Roaming\Adobe\CameraRaw\CameraProfiles
NOTE: It’s sometimes hard to get there because some of the directories may be hidden. To get there faster, you can hit “Win + R” to open the Run program. Then copy and paste the following into it and hit enter:
%userprofile%\AppData\Roaming\Adobe\CameraRaw\CameraProfiles