turn over your guitar... see that 'cover' thingy with screws? usually located right smack in the middle of the guitar or right behind the volume/tone knobs positions. whatever it is, it is behind your guitar la. now unscrew that plastic cover thingy, if you can fit a 9v battery thru that little space, you're usually good to go. remember to insulate the battery by wrapping it with the foam thingy (comes with your emg package) before screwing back the plastic cover of your guitar.