My 2001 Dodge Ram 15000 V-8 has a standard Class 3 steel rear bumper tow rating for up to 7,500 Lbs. maximum trailer weight. The bumper is 21.5 inches above the ground, made to receive a 2 inch ball with threaded shaft and locking nut. How can I modify class 3 bumper for TM "ideal trailer tongue height"?