Hi Chuck - We'll be dealing with 5 parts from interior to exterior: 1)the antenna cable, 2)the ridged silver piece that anchors to the inside of the body through which the cable passes, 3)the unit that the antenna cable plugs into (which is the same piece the antenna mast will screw into on the opposite end), 4) the black piece that anchors to the exterior of the boby with a 19mm nut, and 5)the antenna mast. Unscrew the nut and remove 4. With needle-nose pliers grab 2 & pull it out through the hole, bringing 1 & 2 along with it. Take a paperclip (or clamp, forceps, etc) and use it to tie-off and hold the antenna cable so the clip does not allow the cable to retract back into the hole. Now you've created a work platform. Replace old 3 with your new 3 and seat it into 2. Thread 4 loosely to 2. Now remove the paper clip and with 4 attached, slip 2 back into the hole. Pull up on 4 to seat 2 into place and tighten the nut, drawing 4 over the hole and cinching 2 into place. Screw 4 down onto 2. Once snug and in place, screw 5 -the mast- into 4. That should do it. Keep in mind that 3 has plastic threads for the mast, so be careful not to strip or over tighten.(Been there, done that.) Let me know how it shakes out. Marc