How to update extensions?

I know this is stupid but I don't know how to update the extensions.
I can see for mod_image_show_gk4 that I have missed a lot of updates.
After download should I copy the file somewhere on server?
In Extension Manager the Updat e section is empty.

Hi

None of this extensions uses database of your website, so you just need to replace all files via FTP.

Nevertheless, it's recommended backup of your website.
Basic step for all updates

Thanks.