You don't adjust the cable. You adjust the pads themselves. The way to do that is by pulling the e-brake and releasing it ALL the way a few times. If that doesn't fix it then yuo MAY need to replace the e-brake pads. They MAY have squeakers on them like regular brakes (Most brake sets have 2 plain pads and 2 with a little metal finger. The finger is at a point that it will contact the rotor when the pad wears down to the point of needing replaced. When this happens you get the high pitched squeaking you hear from cars that need new brakes).