You simply copy the package and all dependencies in your
node_modules folder, inside the project for local installation, or in the global folder (
npm config get prefix to see where it is located) for a global installation.
The behavior of
npm install is to check for the dependencies, and install them first. When it doesn’t find them installed, nor the local file containing them, it tries to download them.
Since all of those steps fail (you don’t have the dependency installed, it isn’t available on the expected location, and it can’t download it), the installation fails.
You can find the dependency list in the
package.json of each module, but since it is recursive, it can take a long time to have everything set right if you do it manually, npm does it by recursion.
For you, the easiest way would be to create a new folder on the connected PC, and inside it
npm install angular-cli, zip the folder and transfer it on the offline machine.