The online information for removing the older beta profiles seemed a little abbreviated. I had success by taking the following steps on my Mac:
Quit anything that uses Camera RAW - Lightroom, Photoshop, etc.
Go to the following location on your Mac:
Macintosh HD: /Library/Application Support/Adobe/CameraRaw/CameraProfiles
In /CameraProfiles folder you will find one or more folders with names that have the word "beta" in them. Drag and drop these folders to your trash can, leaving the folders with the released profiles - which are those without the word beta in them. My system asked for a password before I could move these folders.
Relaunch Lightroom and verify that the beta profiles are gone.
If you remove the beta profiles LR will automatically switch to the corresponding release profile. Since applying camera calibration is the first thing I do in my work flow, if there was a change between the release and beta it may impact everything else that I did. You may want to experiment with your photos first before removing anything. From what I have read you can keep the beta profiles indefinitely.
Hope this works for you!
18 March 2018, Sunday
21 hours ago