How to update eclipse in command line?

Question

I want to install some plugins and upgrade some to the latest version. They are not included in the Eclipse SDK downloads. So I must install the individuals manually.

The problem is, the network connection to the update site is very slow. (Maybe 1k bytes per second, or lower) Currently, I have an Amazon EC2 box in us-east-1 region, which is a lot faster to the update site. So, I'd like to install the plugins in EC2 box, and then copy them back to my local machine (in China).

That will look like:

                             very slow, or inaccessible
     My machine @China <-----------------------------------> Update Sites
                                  (1k bytes/sec)

                                        |
                                        |
                                        |
                                        V

                      much faster                         fast
My machine @China <-----------------> EC2 @US-east <------------------> Update Sites
                    (100k bytes/sec)                  (1M bytes/sec)

Now, my EC2 box is running Debian linux, I'm not going to install X windows there, so it can't start Eclipse in GUI mode. Though, I hope I can get updates from command line only.

EDIT

To clarify the question: how to "Install Software" for Eclipse in command line? Since Eclipse is OSGi-based, I guess I can do it using some kind of osgi shell, maybe?