The above is essentially what I did. I then downloaded my "upgrade" and ran the installer. At some point I was asked for my old LR serial number and my new LR6 serial numbers. I supply both. LR6 seems to work ok.
1. I then received email from Adobe saying Welcome to Creative Cloud (some 26 mins before I received my LR6 serial numbers by mail). It seems that despite my attempt to buy the standalone (perpetual) licence I have actually been given the CC version. However, my LR6 splash screen shows Lr and does not show Creative Cloud;
2. After searching some online forums I discover that one can cancel out of CC membership by logging in to Adobe and managing the account to cancel CC. I try this but discover that one cannot cancel a CC trial!
3. I contact Adobe online support by chat to check if I have the perpetual (standalone licence) or the CC licence. They thought it was perpetual. I am transferred to Adobe Technical Support. I am advised that my trial cannot be cancelled and just to wait till it expires. This seems to be 30 days from when I start using it. But I am not using anything in CC!
4. I use LR6 to process a bunch of photos, stopping and starting it a number of times with no particular problems over a few days.
5. I subsequently discover that a perpetual licence installation supposedly shows the LR6 serial number inside LR Help System info. My installation does not. It does however, show "Lightroom version: 6.0  License: Perpetual" !
6. When checking this I discover that I am, unknowingly, signed in to Adobe. I sign out and get a window saying that sign-out will deactivate my LR6 licence on my computer (and can then transfer to another...)! I sign out.
7. When I then try to start LR6, I get a popup window message saying "Sign In Required Please sign in with your Adobe ID". And then saying "Terms and conditions for trial software" and then saying they may ask for optional information to tailor content for me. This was one of the reason why I chose not to get CC. And I did not "trial" LR6 I bought an upgrade perpetual licence! This popup message window belongs to a program called "Adobe Application Manager". It's Help About shows: Version 18.104.22.168 (22.214.171.124). I did not install any such program. I conclude that the LR6 installation bundled it, even though I bought the perpetual (standalone) licence.
8. I do not sign in and quit Adobe Application Manager. LR6 does not start!
9. I start LR6 again but this time sign in. I then get a new popup window from Adobe Application Manager saying "30 Days Remaining" with buttons to "Get started", "Licence This Software" and "Start Trial". I am loath to do anything which places me in any trial that I did not sign up for. I click "Licence This Software". I get a new window seeking my LR6 Serial Number. When I enter that LR6 starts again. LR6 shows me as signed me in again.
10. I repeat the sign out and deactivate process. I disconnect from the internet and try to start LR6. It will not start because I cannot sign in!
11. I contact Adobe Support by online chat again. Their transcript says it took 02:02:51 actual chatting time. They chack my accoutn again and confirm that I bought a perpetual Licence. They offer to give me my serial numbers. I explain that I have them, just that LR6 does not! I am transferred again to Adobe Technical Support. They ask my about my issue with LR4 and LR5. I have none. I explain again that I bought LR6 perpetual but seem to have been given LR6 CC. I am told that if I download LR6 Trial I can convert it to activate LR6. I specifically ask "Are you advising me that the only way to get a LR6 perpetual licence is to first get the CC version?" The answer is yes! I am told I can download it again. I advise that I still have the download.
12. I am advised to just sign in and activate... I do and show them my LR6 Help System info.. does not show my LR6 serial numbers so I do not have LR6 perpetual up and running and I am still in a CC trial that I DID NOT SIGN UP FOR!
13. They suggest I contact www.forums.adobe.com. I do and find this thread.
I would like the following answer please:
1. How can I exit the CC trial and remove any and all CC related programs from my computer (Apple Mac). I do not want it, I do not want to be in it.
2. How can I successfully get LR6 Perpetual (standalone) up and running without being signed in to Adobe.
Any help addressing these issues would be of great benefit and comfort to me.
What do you mean when you say that that is "essentially" what you did? Did you really go to that website, to the link that was provided in the previous answer? Or, did you go to that easy to find link on the Adobe website. If you went to the easy to find link then you have downloaded the creative cloud version. So what is it that you really did?
I went to the same page as shown in that link, clicked on Lightroom the first time, discovered that it took me to the CC verison. Tried again and clicked Buy and then choose upgrade.
So does the title screen or the About Lightroom page indicate that you have Lightroom CC or Lightroom 6? I'm using the creative cloud version. But it's my understanding that if you purchase Lightroom 6 you only need the creative cloud long enough to get the serial number entered and registered. After that the creative cloud isn't needed.
My LR6 startup splash screen shows "Lr Adobe Photoshop Lightroom 6" and says nothing about Creative Cloud or CC.
My LR6 About.. shows "Adobe Photoshop Lightroom 6 version 6.0 Camera Raw 9.0"
My LR6 Help System info shows:
Lightroom version: 6.0 
Operating system: Mac OS 10
Then what is it that makes you think you have Lightroom CC?
Many things.. see my first post.
In particular, the email welcoming me to CC, the fact the Adobe account management shows me as being in the CC trial, the fact that I cannot get the serial numbers to "stick" unless I stay logged in, the fact that my serial numbers do not show up in Help System info (but they do for others who have done the upgrade).
I'm sorry, I am trying to answer questions based on what I understand and not what I know. Apparently there is some confusion about the activation of Lightroom 6. Since I am using the creative cloud installation I will defer to someone who has the answers. I'm sorry to waste your time.
Many thanks for trying Jim Hess. It is appreciated.