There are four bolts on the back side of the spindle. You will also have to remove the axle nut / cotter pin / lock ring / anti-rattle wave washer.
A word of warning. The axle nut is tightened to a very high torque value. The new bearing, (or an old one that is not defective), will be damaged if the axle nut is loosened while the vehicle's weight is on it. Jack the wheel off the ground and remove it, THEN loosen the axle nut. For safety, use a jack stand under that corner of the van. Loosening the nut will be easier if you stick a punch in one of the vents of the brake rotor. It will catch on the brake caliper preventing the axle from turning.
Once the axle nut is off, you can remove the brake caliper and rotor. Support the caliper with heavy wire, or place it where it is not hanging by the rubber hose. Slide the old bearing off, and the new one on. Everything can be reassembled, but the axle nut must be torqued before putting weight on the bearing. Failure to properly tighten the nut will result in the bearing making a buzzing noise, similar to an airplane engine. The new bearing will come with an instruction sheet listing the torque spec. Typical values are from 180 to 250 foot pounds.