If you go through the valve stem you have to take the core out and deflate the tire. Pour them in very slowly. The 90 degree valve stem makes it almost impossible to put them in.
When it came time for the installation of the beads I cut a corner off the bag and dropped it inside the tire. I figured the bag more likely would cause trouble but I've been to 115 MPH and no vibration. Screw pouring them in through the valve stem!