Ask a guy at the store, like at petco or at petsmart or something like that, but ask a person who knows. Be picky about who you ask.
The best format to shoot in - provided your camera gives you the option - is RAW. That has been called a 'digital negative'. JPEG is a 'lossy' format which means that each time you open it you can loose some of the digital information. That does not ...
Consult your owners manual if you have it, I have an 02 Sentra and I believe you have to get at the bulb from the back of the light fixture, ie, inside of the engine. Try the Nissan website and see if you can download a manual in PDF format if you do...