Definitely depends on the specific car. Older cars have a sealed headlight that more than likely can be changed from the front after removing several screws. Most newer cars, say late 80's on, have a smaller bulb that you change out from under the hood (behind the grill).
Check your owners manual, not only will it tell you how to change the bulb, but it will tell you which one to get from the autoparts store/ WallyWorld. And they may not have your exact bulb, but there should be a cross reference list either on the back of the bulb, or in a general manual/little computer to look it up on.
If after checking it out you think it's beyond you, take the car to one of the quick oil change places, they're a little cehaper than taking it to the dealer. Or you could just ask a neighbor or two, I'm sure someone within walking distance from you could help with this.
Difficulty scale 2 out of 10