Idler wheel holder tool for D-Bot Core XY assembly

I found it was extremely hard to keep both bearings and the printed washer lined up and slip in into the housing.I tried many tools to assist but nothing worked. I decided to make my first contribution to Thingiverse and maybe help other with building this http://www.thingiverse.com/thing:1001065 amazing looking printer. Thanks to spauda01 for the great project.