Replicator 2X Extruder Upgrade

I based this upgrade on http://www.thingiverse.com/thing:42250 from whpthomas. Please follow his directions for items you need.

Changes that I have made:
Shorter arm so that it can fit into the 2X on both sides
Big feed hole
Using the top left and right screw holes to hold the base against the motor
Added a groove so that it is possible to add a screw from the front to keep the arm in position
Added a way to hold a nuts at the back for the two screws that will go through the arm