There are two bolts behind the alternator and if you can't find them and get them out, have you thought about how you will get the alternator out after you do get it free? My thought is you need to get more room to work back there. Also, before you remove the left side bolt that's near the serpentine belt, you need to loosen the top manifold bolt it pulls on or the threads will strip.
Take off the windshield wiper bar that's in the way--left side ball joint comes free of the motor cam. Remove the air intake hoses and the MAF sensor and set them aside. Remove the two front engine mount bolts and lift the brackets up out of the way so the engine can roll forward. Block the wheels, put it in netural (battery is disconnected right?). Use a ratchet strap, hook to hole in frame beside driver side A arm under car, run strap up behind bumper, in front of radiator and hook ratchet to engine mount beside throttle cable. Roll engine forward using strap as far as it will go, watching not to crush fans on radiator.
Now you have room. Good luck getting the alternator out of its hole back there. Can you tell I've done this a few times?