Hoi Chummers,

this might have been answered but I havent found something in the forum:

I have installed the browser Exes for the Witcher 3.
With more and more dlcs, updates and the upcoming addons, i would like to make my life easier and use gog galaxy. Is this possible? Like showing galaxy the installation folder? Or do I have to reinstall the game? What happens with my savegames?

Thanks for your help

Here you go:

== IMPORT ALREADY INSTALLED GAMES TO GALAXY ==

1. For GOG games installed using installers from the last few months (so called Galaxy-compatible installers)
Click the "+" button on top of the sidebar and select "scan and import folders" - it will find all compatible games within that folder and add them to the Client.

2. For remaining GOG game INSTALLATIONS
Find the game in the Library (click on the image of the game), then click the More button and select "Manage" -> "Import folder" and point the folder selector into the folder where that game is installed.
Please be aware that Client will accept any folder pointed to and will overwrite files inside it (this can for example wipe some mods or damage other apps in case of pointing to a wrong folder) and will update the game to the newest version (current default language English).

Source: http://www.gog.com/forum/general/gog_galaxy_beta_2/post1

Magic! It worked!
Thanks man!