UPDATE OCTOBER 2017: Click here to go to a newer version of this article on where to find the Lightroom 6 product. The article below is out-of-date.
For those of you who prefer to continue with the stand-alone perpetual-license version of Lightroom rather than the Lightroom CC subscription, and want to upgrade to Lightroom 6 from any earlier version, I’ll show you in this article how to find the Lightroom 6 upgrade on Adobe.com. Yes, it is difficult to find – Adobe would prefer you purchase the subscription, but nonetheless they are still offering both options. (If you don’t like Adobe’s tactics, please don’t shoot the messenger.)
Before you purchase, I would recommend reading my article, Which Should I Buy, Lightroom CC 2015 or Lightroom 6?
How to Find the Lightroom 6 Upgrade
1. Click on this link to go to the Adobe Product page.
2. Scroll down, find Photoshop Lightroom (it may be on page 2), and click on Buy (ignore the price).
4. On the next screen, change “Full” to “Upgrade”, and select the version of Lightroom you are upgrading from: 
At this point you should see the $79 price and can proceed through the checkout process.
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Laura,
Many thanks for the information. Despite being a user since Lr1 I have been actively searching for an alternative. Your guidance came in time for me to somewhat reluctantly go the upgrade route. (The learning curve on a new product was too daunting, but it was close – I am averse to ‘creative clouds’…).
But don’t they make it difficult? – lots of hoops to jump through. I have just gone through similar pain dealing with Comcast. Being compared to a company notorious for their lack of customer service says a lot about how Adobe has changed.
Agreed. I wanted to update from version 5 to version 6.
Every attempt is blocked by a message that my email address resorts in a different country to the original address used when buying my first subscription.
It seems to be impossible to correct this.
Looking on the internet it appears that I am not alone.
Adobe seems to have joined the list of customer unfriendly suppliers!
After all who needs satisfied customers?
Thank you Laura.
Adobe hides it really well.
Hi Laura,
I sincerely thank you for taking time to respond to a year old post. You do make a compelling argument to switching to CC2015. However, I still have questions I haven’t been able to find the answer to.
Does CC allow for the catalog to be maintained with the images on an external HD? I still don’t understand how to use CC on 2 computers? How do I share presets?
You’re welcome, George. These aren’t CC-specific questions, as it works exactly the same for CC and 6 (and earlier versions). Yes, you can store the catalog and photos on an external drive. Here’s an article on how to work with two computers. This is covered in more depth in my Lightroom CC/6 and 5: The Fundamentals & Beyond series, specifically the videos on Organizing and Backing Up and on Moving Your Photo Library. Regarding presets, in Preferences on the Presets tab you’ll choose to store your presets with your catalog (on the external drive, so they will be accessible from either computer.) If you have presets already, you’ll have to copy them into this Lightroom Settings folder within your catalog folder. Sorry I can’t go into all the details here – covered in the Preferences video of my series.
Let me add, George, that I suspect you’re being thrown by the “cloud” portion of “Creative Cloud”. Nothing gets stored in the cloud though – not your software, catalog, photos, presets, etc. The cloud is just used to sync your photos, if you choose, to and from your mobile devices and lightroom web (a web browser way of accessing and working with your photos, but this is not the main way – that’s on your computer.)