When I used to do my own service I started by buying an easy-drain sump plug. buying a second hand car, I always gave it a thorough service first thing, plenty of engine flush to make sure all the old oil is out. remove the plug, drain oil then install the easy-drain. Next service you remove a cap, screw on a tube & it drains (they worked on the same principle as the hozelock self-seal quick fit attachments).
Last one I bought would have been about 13 years ago.
My motor is still under warranty at the moment but I'll be doing my own service soon - maybe. Sometimes it works out cheaper to get a garage to do it, especially if they can cancel the service light!
Sorry, I know it doesn't solve the problem you have, but for future reference.
BTW, I take it you've tried with stilson wrench/mole grips & lots of heat to the area around the bolt?