Volvo Repair: Flush Gas Tank, jumper wire, plastic tank

Question
I have a 1990 740 STD Wagon.  Someone emptied the contents of a fire extinguisher into my gas tank.  Is there a plug to easily drain and flush the tank?  or should I drop the tank and flush it that way?  Any advise on this fix it job would be greatly appreciated.

Answer
Michael, I just love when people do stupid stuff.  Anyway, you can do it 2 ways.  Add a few gallons to the tank, disconnect the fuel line going into the injector rail, bypass the fuel relay by using a jumper wire to make the pump run and all the fuel will be pumped out that way, or take the tank out and have it flushed and purged.  You should have a plastic tank on that model so a  drain fitting is not on that tank.  Hope this helped.  Roger