2001 E320.

Helping my friend with a transmission leak. The transmission leaks around the passenfer side, front corner of the oil pan. We replaced the pan gasket did not solved the problem. After examing it more carefully, it appears the leak is coming under an electric plastic plug right above the pan at that corner. I think it is called "plug adapter" based on the parts diagram CD.

It appears the plastic plug is simply pressed into the transmission body. There is, well was, a plastic tab allow me to insert a flat screw driver and pry it off the transmission. I BROKE THE TAB!!. It is too tight. I hope this does not ewquire a special tool.

Can someone suggest how to get this electric plug removed/replaced?