Thanks, but it do not go. When I say I try to purchase an actualization from 5 to 6 there is no option to do it.
You have to click the BUY button then when the next screen comes up there is an option to select either the Full version or the Upgrade (NOTE that is UPGRADE not Update) version.
You don't need to select a Previous version. The Upgrade works with all version of LR from V1 to V5.
The instructions have an extra popup, now, where they're trying to push you to buy the CC Photography Plan, and you have to click Buy Now on that, in between:
Go here Products
Click Buy next to LR then click Buy Now on the popup:
From the Cart view, change the Full to Upgrade, then click Save Changes and you should have the Upgrade price:
Be aware that LR 6 purchased this way won't get feature updates and you'll have to wait for LR 7. LR CC 2015 that is part of the Photography Plan will get feature updates where Dehaze is the first LR CC-first feature.