The problem with pulling the alternator out after bolt removal is the long bolt sleeve at the rear of the alternator. Once the bolt is out, use a screw driver to pry or push the bushing rearward. Some penetrant spray and vise grips to turn it slightly will help.
Then the alternator should lift out from the top. Battery should be removed for this, and the tray too if possible. When the new alternator goes in and the bolt is tightened, the bushing will be pulled back to its original location. Hope this helps.
'97 XJ Moss Green Metallic. 2DR. 2WD AW4 tow pkg.,3.73 gears. Firestone Destination A/T 225/75x15.