There is no way to convert a 2011 Solidworks model/assembly/drawing to an older release of Solidworks.
Your only option is through a neutral format such as parasolid/step/iges.
You could write the .slddrw back as a PDF for viewing purposes, or let him view it with Edrawings.
But you won't be able to directly give him your models drawn in 2011 whatsoever.
Thanks man. The reality is so bad.