I've searched the forum several times,with no luck,so here goes. I just bought the Hirschmann antenna motor to replace the original on my '90 300E sedan. PROBLEM: How to remove the screw-on nut,so I can slide the antenna up from inside the trunk.The little rounded cap that is at the very top of the antenna prevents the removal of the little nut. Do you have to remove the mast and wire in order to do this??? Totally lost. Any help is appreciated!!