Use Losi glue straight from your freezer. It'll give you about 5 minutes of slow cure.
Mount your tires up just as if they were glued and ready to run. Push one sides bead back into the center of the rim. The Losi glue bottle tip is a perfect fit into the 2.2 rim where the bead goes. Run the glue completely around the rim and them pinch your tire pulling your bead into place one inch at a time going counter clockwise (each inch adjusting the bead into place). Repeat on the other side and put rubber bands on to cure.
Take the rubber bands off and pull the side walls back putting glue into the gap. Do both sides and put the rubber bands on to cure.