This mod slides right onto the Makerbot Replicator Dual Extruding beauty. I printed it with .2 on ABS. Then you'll want your bot to print itself a mustache that fits into the screw holes. I used Monseñor Replicator's Mustache thingiverse.com/thing:34423.

I had an issue with the switch, which you may or may not have. I'm copying the following instructions from ColinBB's instructions. I cut a little slice to make it work.

"You may, I have not, run into a problem with the X-Endstop switch not engaging due to the extra thickness of the print. If this does occur, there are a couple things you can do. One, is to alter the thickness of the right wall. The second, is to pull the switch toward the center of the machine by a few millimeters. This should be done with a light hand."