Jan Naslund (812053) Is there a step-by-step instruction on how to upgrade TopSky?
There's not, as there are so many variables involved - the main one being the version you're upgrading from.
From a recent beta, the minimum required action is to replace the old plugin dll file with the new one. For an already working setup, it's not usually necessary to replace any other files. Very generally speaking, when updating, there's a good chance it goes well if you update only those files from the package that have a newer "last modified date" than the ones you already have.
If you're upgrading from a very old version (say for example 2.4), after replacing the files, the next step would be to dive into the developer guide to see how the settings should be changed.
The betas are certainly not meant for sector file developers, but to anyone wishing to use them, having an interest in new features and not being allergic to reading documentation. It just so happens that many sector file developers belong in the group of people meeting these criteria.
Incidentally, a couple of hours after releasing this beta, I received some crash dump information that should allow me to eliminate a couple of CTD scenarios, so most likely there will be a new beta in the near future. The crashes were from versions prior to beta 12, so there's no reason to not use this beta until a newer one becomes available.