Open the cool.bpg project file. This project file includes the runtime and the designtime package. 

In the project manager double click onto the CoolDTPackage.bpl item to open the package manager. 

In the package manager click onto the install button. That should compile and install both packages in the IDE. In my case there is always an error message popping up that says, that the CoolRTPackage can't be installed, because it's a runtime only package. Just hit the Install button in the package manager again and all components get installed.
