there are informations about your interests here: http://prodesigntools.com/adobe-lightroom-6-cc-direct-download-links.html >>> See: Importantly, this new version continues as a downloadable desktop product and is available either with a standalone perpetual license (called Lightroom 6) or via subscription (called Lightroom CC). It’s the same exact program and free trial download below, but the name is changed to reflect the differences in licensing and bundling, as well as the addition of integrated mobile apps & services and future feature updates.
From there you will find a download link.
Try clicking the menu in LR5:
Help >> Updates
Thank you all for the responses. The Help-Update option gives you the updates of 5 ( for example, the last update was 5.7). I managed to locate the store and buy the upgrade version from 5 to 6... Thank you all for the responses.. an