VW Beetle- coolant temp sensor

Car is my dad’s 2004 VW Beetle- attemping to replace the coolant tempeture sensor- comes out pretty easily, removed wire conection and then plastic retaining C clip and pulling sensor out like a plug- Now I can not get new sensor to seat the last quarter inch needed to get the plastic C clip over the ridges on the sensor-

Is there some trick or tool needed to get the sensor to seat? I tried forcing it by hand but no luck- still a quarter inch too high-

(Haynes repair manual on order but need help now)

Thanks in advance for any information.

It has been a while since I did mine. As I recall there is a gasket that may not come out with the old one. Make certain there is not an extra gasket there.

I was looking for a gasket or rubber ring in the tube that the old sensor came out of but could not see one- I felt in the tube with my finger and could feel a rounded ridge that I figured sealed the sensor- didn’t feel much like rubber but maybe it was just old and hard- the new sensor did not come with a gasket so I was unsure if one was reqwuired- perhaps the ridge I felt in the tube is ment to be a permanent, nonreplacable seal? Am I just not appling enough pressure to force the sensor in?