You can run the examples like this:

$ ant run-reader-examples "-Daccess_token=MY_ACCESS_TOKEN"
$ ant run-publisher-examples "-Daccess_token=MY_ACCESS_TOKEN"
$ ant run-legacy-examples "-Daccess_token=MY_ACCESS_TOKEN"

Instructions for getting an OAuth access token are available on http://restfb.com.
Apache Ant (http://ant.apache.org) must be installed to run the examples.