Where do you add fluid for the front axle after removing it

Where do you add fluid for the front axle after removing it Right passenger front axle was removed on a 2001 Ford Escape 3.0L V6 4WD to gain access to the alternator. We assume the axle fluid coming out is ATF fluid on the front. Someone said pour some back in there until it runs out. But wouldn't there be a place to fill it