Just import the project files. Each one comes in contained in its own folder.
If something ELSE is happening, you'll need to describe it in greater detail. Screenshots of the ENTIRE user interface are good.
As mentioned by Dave, you can simply import your After Effects project files in a new project.
You can see all the assets in the Project Panel.
This action imported the other project files, but the timeline (and all the work) was lost. Any other ideas?
What do you mean "the timeline was lost"? When you import another project, open the composition that gets imported and you should see everything.