http://www.mediacollege.com/audio/co...xlr-rca-1.html
It's not hard, just tedious because of the small tabs you need to solder to.
A simpler solution is to get a mono 1/4" (tip-sleeve) to rca plug adapter and then just use RCA cables.
http://www.radioshack.com/product/in...entPage=search
I have run BFD units both ways and they work just fine.
Good luck and let us know how it turns out.