Items selected inside of the Component List can be edited inside of the property grid on the right side.

Any changes to the component will lead to the green dot turning orange. You can save the changes by either clicking the button above the property grid and saving or pressing the save option in "File" in the top row. Until then there are no changes that are actually saved and applied to the real components. If you select multiple components at the same time, or use the Sum Up which leads to a row representing more than one component, the property grid will show you only the values that are the same between all components. Any changes inside of the property grid will then edit all objects at the same time. Properties shown are not necessarly present in all components selected. If one component has the property then the property will be shown. If a value is then edited, the components that do not have the property will be given the property.