I want to replace the images displayed there with my own images (Already have the .aep). How do I change the images? (Basically replace)
Here are a couple of relevant tips from the section of After Effects Help about footage items:
To replace the source footage item for a layer with another footage item, without affecting changes made to the layer properties, select the layer and then Alt-drag (Windows) or Option-drag (Mac OS) the new footage item onto the layer in the Timeline panel.To replace all uses of selected footage items with another footage item, select footage items in the Project panel, and then Alt-drag (Windows) or Option-drag (Mac OS) the new footage item onto a selected footage item in the Project panel.