Plea Letter for accepting my insuficient 2hr course in BS

I got my BS(Civil Engineer) form Australia and my master(Construction Management) from USA,I did accredited evaluation through neccs and they gave me 2hr insufficient hr in general course .I talked with one member of board and he recommended me to write plea letter to show that my experience and my master are covering 2 hr of general courses.I have 7 years experience in civil engineering and civil project management.anybody has any idea how to write strong plea letter,otherwise i need go to back to school.thnx

I took the CLEP exams to cover the General Ed "deficiencies"  just to avoid dealing with Boards and possible hoops that they would likely ask me to jump. It's annoying to give those exams but I'd prefer that than dealing with state Boards in this matter. Just my personal preference.