Yes, should be easily changed from the top. Buy only Bosch reman unit or
new. However, you could try one thing before you replace it entirely...
replace the voltage regulator instead... $25.
You can install the regulator without removing the alternator... it is
accessed from the back and only has two screws.
Price for reman Bosch is $177 and $100 core when you return your old unit.
If you should decide to replace your alternator... replace the belt and
tensioner at the same time... your tensioner is probably orignal too.