Installing, repairing, and removing components from your starships is accomplished via a Ship Component Management interface on a Starship Terminal. The manager is split into four main areas that help you organize and compare your ship components while viewing their visual appearance on your ship.
The list on the left displays all slots your ship chassis contains for placing components. All ships share some key component slots—reactor, engine, front/back armor, capacitor, booster, etc. -- and also contain specific slots, like weapons, ordnance, and cargo holds. Double-clicking a slot will expand it to show all components in your inventory that can fit in that slot; selecting a component from this list will show it in the Selected view to the right, allowing you to quickly compare its stats to the Installed component. Finally, double-clicking a component (or pressing the Load button) will unload an installed component and replace it with the selected one, provided your ship has enough mass to hold the new component.
You can repair damaged components already installed by selecting them and pressing the Repair button in the Installed window. The component will be repaired if you have an appropriate repair kit in your inventory. This is the only way to repair your reactor and engine if they have been disabled and you somehow ended up on the ground without repairing them.
The bottom display shows your ship as it will appear in space. Different components modify your appearance in various ways: blasters come in a variety of styles, as do engines, so you may wish to mix and match them to achieve the best looking fighter. The display also shows your ship's chassis hitpoints, current and maximum mass, and reactor output/drain.