w126 alternator

[bengerman]

i believe my alternator is shot.
i say believe, because no professionals have checked it, but my more-car experienced friends have told me that's what my symptoms indicate.

when i got the car, i was told the battery was bad, because it needed to b jumped if it hadn't been driven for about 3 days.
ok. changed the battery.
she works.

for about a week.

then, today, i go to start her up. nothing. no sounds at all.
my friend tries to jump it, she doesn't start, but i can hear her try. and the radio turns on, but she's not quite there.

so, i have two questions.

does this sound like an alternator to you folks? anything i can check myself to be sure?

and

how do i go about changing the alternator, if this is the question?