All of the downloads for extensions I find are .dll, but the installation instructions require a .fb2k-component file. How do I install the .dll files?
Open File>Preferences>Components. Drag the dll(s) from Explorer on to it.
Oh, thanks! Thought I tried that already.
You probably got an old component in a foo*.zip file? From Preferences -> Components, click Install and select the .zip. Without extracting!
The more recent ".fb2k-component" suffix is just a renamed .zip
Idiotic web browsers like to rename .fb2k-component downloads to .zip. You know, because renaming to match the server reported MIME type is less confusing to the user.