The plug has a small, raised lip on the outside surface. You need to insert a thin, electrical screwdriver diagonally from the top of the housing, and about a centimeter down, from where that plug is inserted. (there's an obvious insertion window, there) Now lever the housing gently away from the plug, whilst pulling on the plug. It should come away. A tip, here ..... file off that raised lip, so that it can easily be separated in future! Those DRL's that you have ordered are not identical to mine ..... I'd be interested to know just how bright they are, in daylight ..... Also, especially when looking at the indicator light, they do seem to be more "individual" LED's, and not strip? Anyway, that's a good price! You will have to run a wire from your light-switch to the headlights ... it's all in this thread!
David