the headlights on our cars are sealed beam headlights, which means that the bulbs are permenantly inside the headlight housing. this either calls for 1 of 2 things...
1. a new sealed beam headlight. which you can get at ur local autoparts dealer. just either bring in your headlight and have them match it to yours. in the states our code for the housing is 6054 i believe but im not sure about the uk.
2. a new housing which can use replaceable bulbs. these housings allow for you to replace only the bulbs of your choice. if you do go this route many have said that hella ecodes are a very good housing. if you like go to www.celicatech.com
and go to the exterior/interior section, there should be a thread about it there. good luck to you hope this helps