Scroll down to near the bottom to LR 6, click on Buy, change "Full" to "Upgrade"
And just so that there's no confusion, LR 6 will not have certain features that are added to LR CC, like dehaze, black and white local adjustments, and any other features added to LR CC before LR 7 comes out. Then LR 7 will have all of the mentioned features that were added to LR CC.
Hi dj paige: Thanks for the link. I've been there before and clicking on the "buy" button brings up a box that does not provide the option to upgrade, as this image shows. The "No upgrade" text was added by me for this screen grab, which is of the page your link sent me to. I'm in the US so there shouldn't be any regional issues. Clicking the "buy now" button takes me to a shopping cart ready for checkout. Any other suggestions? I also logged into the Adobe online chat help line and waited for over half an hour with no one answering.
If you click on the "Buy Now" in the Lightroom 6 box underneath the $149 price, you will be led to a screen where you can change from full to upgrade. Then when you check on the yellow "Save Changes" button at the bottom of the screen the total price will change to $79. Just follow the prompts on the screen and you can purchase an upgrade.
@ jimHess: Bingo! That text where it says, "I want to buy..." was much too small for my 70-y-o eyes. Thank you so much for the added help.
@ dj paige: This is not to diminish your good advice. If I had looked squinted closer I wouldn't have had to ask for further details.
Thanks to you both for your help. Enjoy your week!