where is the altertnor hard to change for the 1997 chevrolet lumnia

Refine your question. To change the alternator first you must loosen the belt that is connected to the front pulley. To do this, there is a belt tensioner. Then mark and remove the wires going to the alternator. Any shrouds or covers need to be removed. Look next for the bolts that hold the alternator to the front mount and loosen and then remove the bolts. You should then lift off the old alternator, put the new one in place and reverse the process. Make sure after connecting the belt, the tensioner is properly in place and gives tension to the belt. Double check the wires to make sure they are correct as per you diagram when removing it, then remove all the tools and rags from the engine area and start the car. WA-La, it's done.