Hi Scott,
This is where long handled screw drivers come in to play! as long as the jubile clip is facing the right direction,
Best way is to fill back up, remove rad plug, fill it up, replace plug, top up expantion tank to half way, run it for a while, keep an eye on the level at the tank, it should drop after a while, keep topping up to half way until it holds its level.
When running for a bit, turn your heater on to see if its getting warm.
If its not give the top hose a few squeezes, This can move any air locks around and out.
Take it your trying to drain the rad?
Ian