Hiya David 
I am not sure there is a way to do this, but I do know that in the script/console (which is an irb session with your rails environment), you can do:
Dispatcher.reset_application!
to reload everything, it grabs the changed files, I believe (at least in dev mode).
and you can specifically load one again by calling:
load ‘class’
instead of require, as require won’t do it if it’s already there.
So, I don’t know if you can do it in the code as it’s running on a web server in production mode. Wouldn’t it be better practice to just restart the app?
Hope that helps.