1999 chrysler 300m radiator leak

My 99 300m has suddenly sarted to leak from the passenger side of the radiator. I can't get any heat inside the car even though I made sure that the system was full. I let it idle to see if it would start blowing hot air and the water started steaming and blowing out of the resovior. Anyone know what's going wrong? Is the thermostat stuck? The temp gauge showed that the car was not overheating during all of this.

I also have to change the oil pan as the previous owner stripped the drain plug. How hard is it to change? Do you have to unbolt the engie mounts to raise the motor to do this? Any hints to make this easier would be very appreciated.

Thanks

Obviously you have many issues. Here is a link to the FSM. Download it to your computer so you have it for future reference.

http://www.dodgeintrepid.net/forums/showthread.php?t=94402