it is not very hard, its only 2 bolts holding the alt, 2 wires on the back, 1 belt to untension (there is a hole you can put a pin or drill bit in to holt the belt tensioner released) but remember to disconnect the battery because the main wire is unfused. the pullies are usually just one bolt.
Its just under a 2 hour job to replace the alternator. It's always best to have proper instructions and illustrations when doing any job you may not have done before. Autozone have some popular workshop manuals for free on line once you register (for free) on their website http://bit.ly/autozone_repair_info .There is a company that independent auto repair shops "buy" their information from that offer a very reasonable service to do it yourselvers. You get a one year subscription to year make and model specific repair procedures, service bulletins, component locations, wiring diagrams ect.... great quality information same as the professionals have ,much better than generic workshop manuals from parts stores, much cheaper than the factory manual. http://bit.ly/alldata_repair_manuals or try http://bit.ly/mitchell_repair_manuals_online and get an online repair manual subscription.