They are each held on with two large bolts and some marked washers. They are pointed out in the picture with yellow arrows. I don’t know how important it is to keep the driver side parts separate from the passenger side parts, but I kept mine separate (because I’m anal like that).
Rather than put the driver and passenger side bolts and washers in their own zip-loc bags, I simply removed the control arms and put these bolts and washers back in their original places on the control arms. Set the control arms aside. They will be reinstalled later.
This picture is taken of the driver side. I’ve suspended the axle shafts with wire coat hangers. I don’t know how important it is to keep them from hanging freely so perhaps it’s not necessary to do this, but it is easier to slide in and out from under the vehicle when these are out of the way.