Yes, you can change out the alternator pulley very easily. I happen to have a stock alternator pulley that I just removed from my low mileage SRT6. You can have it for $20.00 delivered to your door.

I find it highly unlikely that all of those pulleys failed (are failing) at the same time. In any event, you can definitely R & R the pulleys yourself but as grip grip said you'll need a special tool to "hold" the crank pulley while removing the bolt and replacing the bolt (you should also get a new crank bolt). That bolt has a VERY high torque and the bolt is difficult to remove and also difficult to re-torque correctly.