Headlights replacement?

Hello there! For a long time, my car's headlights have been a little vit cracked and I noticed that water started to get in, so I think it's time for a new ones. I'm asking for advice about what I should be careful about and pretty much how is this job done. All I'm seeing is a bolt over them, is the rest being held by clips or something else? Also, I have noticed that there are 2 different kinds of headlights that you can buy for this car, and both are halogen my is with the original normal lights, I guess my question here is do they use the same old wiring or something needs to be changed there apart from getting halogen headlight bulbs?