2002 BMW Z3 altenator removal

There are two bolts holding the alternator in place. One bolt is behind the cover cap for the deflection pulley, and it has a 16mm bolt head. The other is beneath the alternator, and it too is 16mm. The alternator is fixed in place and does not adjust to the belt, there is a tensioner that pushes an idler pulley into the belt, and that what is what holds tension on the belt. There is a dust cap on those pulleys and if you pop them off you will be able to turn the bolt in the center of the tensioner pulley to load the tensioner to remove and replace the belt. Once all the bolts are out you can wiggle the alternator out of there, it does not come out easily. Replace in reverse order.