Just did exactly this last Friday. Bought D3S 6000k HID bulb and replaced with OEM one. As mentioned above, it requires removal of front bumper because each headlight housing have 3 bolts and one of them is hidden under the bumper.
If you have experience with removing the front bumper, this shouldn't be much of issue, but if you haven't then I would recommend going to local body shop or reach out to fellow handyman.
Should you attempt this yourself, quick advise would be have a magnetic Philips driver ready, which will come handy once you open up the dust cap of the housing. The bulb is held by a metal bridge(? for lack of better word) and tightened with two small bolts which need to be unscrewed if you are to remove the OEM bulb. It's really easy for that bolt to fall into the housing if you are not careful. (Boy I wished I had one of those magnetic ones when I encountered it)
Good luck and you'll enjoy matching color of HID and low LED DRL once you got them done.