I use Osram Nightbreaker Plus H1 bulbs too, only because I could get hold of some sooner than a set of OEM. Well priced for a good quality bulb and throw decent light. As for fitting (FL model), slightly tricky and will possibly involve a few swear words. The passenger side is easier due to there being more room.
Remove the plug from the back of the bulb, then the round rubber grommet/seal, then to remove the bulb, there's a metal spring clip type thing with a small loop at the end, that's the part you need to push in then to one side slightly to unclip the bulb. Once that is unclipped and pivoted down out the way, remove the bulb taking care not to remove at an angle through the small hole causing the glas part of the bulb to snap off inside the light itself. (If this does happen, use a vacuum cleaner's nozzle over that hole and that should remove it)
On mine, there's awhite/beige butterfly adaptor with two prongs on it, separate that from the bulb, replace with new bulb then repeat this process in reverse to re-fit. Don't touch the glass part of the bulb with skin/oil/grease etc, possibly use rubber gloves. Hope this helps.