Conversion of (X,Y,Z)ECEF to NED

I managed to convert the geodetic latitude, longitude and height of the vehicle into XYZ of ECEF. However I need to convert into NED. Is there any conversion? Does it involve with a 3x3 matric?

Thanks.

[Walter Roberson]

Is there a difference between this question and your still-active question http://www.mathworks.com/matlabcentral/answers/26280-conversion-of-ecef-to-ned

[Casey]

Slight different, i guess. The still-active question was converting from geodetic latitude, longitude and height of the vehicle directly into NED. While else this current question from the conversion of XYZ into NED. To be honest, I am not very familar with both of the conversion thats the reason I post another question.