right if you look on candle power forums there are instructions ,but it is quite simple .when you remove old bulb and comapare it to new bulb ,you will see the top tag needs to be trimmed,took me 20 mins to remove old, trim new and refit old bulbs output 1000 lumens new ones 9012 hir2 out put 1850 lumens, at night on country roads difference is great as long as your headlights are properly set will not cause dazzle to other drivers unlike retrofit hids