The usual method is to disconnect the battery, remove connecting wires ,
remove the belt, then unbolt alternator from its mounting bracket. This
is followed up by installing the replacement alternator. The operation is
now done in reverse, ie instead of loosening bolts you tighten them,
instead of loosening the belt you tighten it, instead of disconnecting
wires you connect them.

The key to success is to recognize what an alternator looks like. You
don't want to remove your oil filter or worse the engine tappet covers by
mistake. Here is some information to help you recognize your alternator
http://en.wikipedia.org/wiki/Alternator#Automotive_alternators