I replaced the battery in my stratus about 1 year ago. I've been driving the car fine for awhile.

Today I went out to start it and nothing happens when you turn the key. Pretty sure the battery is dead, however why would it just die? No lights were left on. Seems that something is draining the battery or not charging it. Could my alternator be bad?

If so, what are the replacement steps for an alternator in a 2.7l stratus?