This being my first game of MoO I'm playing the Klackons as suggested by the manual.
Since Klackons get a bonus in Construction I figured I'd concentrate on building factories first to get a good production going. As I was reaching the max limit of 2 factories per population I researched Improved Robotic Controls III, which should allow me to build 3 factories per population. But I can't find any way to actually REFIT the factories, and the Ind Production bar still says MAX. Keeping it at Max and hitting the Next Turn button just puts the RPs into the planet's Reserve.
So what am I missing here?

"MAX" means that the planet can't build more factories until the planet's population increases. "Refit" will occur automatically once the appropriate tech is researched and there's enough industry production to cover it; if you have the industry bar set high then it will probably occur on that turn and additional factories built as well, so you won't ever actually see the "REFIT" status.

In this case, you need to bump up the Eco bar until you have enough additional population to allow for more factories.

Oh well, it turns out I misunderstood.
I thought the inventions listed under each of the six technologies were already researched, but it turns out the last one listed in the one currently being researched.