RE: install a tailwheel
Well assuming you have a DuBro 955 or 956 it is designed to attach to the bottom of the fuselage and the U shaped piece is designed to attach to the rudder. Then the springs run from the rudder to the tiller arms above the tail wheel. It's pretty simple. The tail wheel bracket does not attach to the rudder only the U shaped piece so all the force is applied to the fuselage.