Clean the exterior of the TA to prevent dirt from coming in. Using the same logic of keeping things out that don't belong, you will need to crack/ split / or pry the plug out. It may be necessary to invert the unit or even possibly drill to help extract it. You may have a better idea once you receive the replacement plug.

What worries me is if it was melted to the tranny like that, is what other damage is inside the transaxle..heat is definitely an enemy to these.....

True, but at this point you are out some oil and some time.