Eat carrots and next time remember to buy one with decent lights to start with, cheaper this way....
Depends.... might be lots of carrots though
Sounds like you have halogens, in which case Osram Nightbreakers probably easiest way to better dip and main.
The round circular lights on some models are commonly called angel eyes, sometimes they can be quite yellow, there's lots of entries on here how to upgrade to LEDs - that's just for those angel eyes, it is though a fairly easy and common upgrade.
BMW being the nice folk they are, have lower spec cars with daytime running lights that are not angel eyes... just sort of sidelights, while it IS possible, changing to angel eyes could be expensive.
Snowblind did a cover of what he did to upgrade dips to LEDs and the results looked good, but ended up with a bit of custom bulb mounting to get that source of light in the right place, it does matter as it defines the light throw.
realoem.com and last 7 of your VIN might help.