It does have its own built-in method, I think. From skimming the tutorials at PerlMonth, it looks like you just declare the argument in an %args section, then just use the variables as $user and $knowledge. The variables are created as my variables lexical to the component.

So:

<%args>
$user
$knowledge
</%args>

User: <% $user %>
Knowledge: <% knowledge %>
[download]

Have you looked at the tutorials? They might be helpful:

Part 1
Part 2