<p>How do I deploy an ADF business component to the middle tier and call it using <a href="http://en.wikipedia.org/wiki/Java_remote_method_invocation" rel="nofollow noreferrer">RMI</a>?</p>

<p>I just cannot find any good documentation on this!</p>

I guess you mean something like:
How to install ADF 10 runtime and deploy ADF BC app to Oracle WebLogic 103 running on Linux
Oracle Application Development Framework - Development Guidelines (10g)
(PDF format).