the best thing to do is to completely take it off, and re route the belt, its what i did and many others, this makes the belt shorter and all the accesories to work less. heres a link to a previous forum a/c delete
Without doing anything else, take the serp belt off and spin the A/C pully with your hand.. thats the amount of load that it adds to the engine as of now. You can decide if its worth pulling it off. What you will get is 15 lbs of weight savings and more room in the engine compartment. Don't expect to gain HP by removing it and/or replacing the pulley with a delete pulley.