I may not understand your question.
Yes you can change the actual bulbs. I highly doubt that the actual bulb is your problem though. The light assembly reflective surface or the outer lens is your problem. Changing the actual bulb or the light source is not going to help you.
To change the bulbs, look behind the headlight light. There is an electrical connector, a big black plastic circle that twists off and probably a small metal clip. The bulb is behind all of that.
ok for these lights you probly need to pull that whole assembly for the actual headlight off the car......my lights are similar to those and because there are two bulbs instead of one the individual housing for the bright and dim bulbs are off set and cant be removed without removing that whole middle section
mine only use 4 of the nuts to hold them on total since its a one piece.......his are the three piece so it will probly use the same number as stock.....but he should only have to pull out that middle piece......