Once you buy the Mod Calibrator and get all the materials/energy/crowns that you need, Just use the red Alchemy machine to the far left of the arcade. The recipes are built-in, so no need to learn a recipe. Just select one from the list once you interact with it, and boom, there is your module. However, you need to craft the 4* version of a module first before upgrading it to 5*, much like any other craftable item. 4* things cost 400 energy, and 5* cost 800, so come with enough.