First, prepare your env:
virtualenv .venv
.venv/bin/pip install pexpect configparser==3.3.0r2 gevent git+git://github.com/mozilla-services/loads.git
Then write your tests and run them:
.venv/bin/loads-runner --config=./config/megabench.ini --user-id=mat --server-url=http://some-server.tld loadtest.TestCase.test_all