It's generally easier to start by installing the cross into the inner axle first. The cross is installed into the yoke with the chamfers towards the shaft portion of the axle and the full-circle C-clips installed on the trunnions. The clips will impede easy insertion of the cross, but if you maneuver it all just right, it will slip together. Put the small O-ring into the first groove of the brass pistons and install the spring and plungers into the recesses of the cross. Use only a little grease on the O-ring.