In order to tighten the wheel bearings on your Jeep, there is a couple of things that need to be done. First, the front bearings are Hub Bearings, and are part of a hub assembly. If the bearing is loose, then really the only thing you can do is replace the hub assembly...Part # 5016458AA from your local Jeep Eagle Dealer. You remove the the wheels first, then the brake caliper, then the rotor and the ABS speed sensor. Then remove the cotter pin and the nut retainer and the axle nut. Then remove the 3 retainer bolts from behind the steering knuckle. The Hub will come right off.
Now, if the retaining bolts behind the steering knuckle are all that is loose, just tighten them, but that is highly unlikely.