If you are referring to the lamp that lights up when you open the doors and is located over your head. You carefully remove the plastic cover being sure not to snap anything. Inside will be either what looks like a bulb or a fuse and you take that out, carefully too. You take it with you too the autoparts and get replacements. Reinsert the same way you took them out and gently snap on the cover. If it still doesnt work then that can be a fuse located in the fuse box. Now sometimes people refer to the headlights as head lamp and in that you cannot replace the bulb you have to buy the whole lamp from either a autoparts or dealer. With this you lift the hood and look behind the lamp. It should be inserted into what looks like a plug. You disconnect the two gently and be sure to not disconnect by the wires, hold them by the connection pieces. You may want to disconnect the battery before doing this too.