Volvo Repair: Replacing 2001 Volvo Antenna Mast, antenna mast, rubber body

Question
Mark,  Botton section of antenna mast bent in carwash. Bottom section of antenna is fully extended and so crimpt part is exposed and above mast nut.  I purchased an OEM replacment mast but cannot get the mast nut/fixing nut off to remove bottom section of old antenna.  It unscrews and comes up out of rubber body washer about 3/4 inch but at some point will not unscrew any further and will not lift up.  It seems like it is somehow still attached to the main motor body in the trunk. The rest of the old antenna and the entire white cable came out when the radio was turned on.  If I could get the mast nut and the lower section of the old antenna out I feel certain I could install the new antenna with no problem per instructions.  With the mast nut stuck I'm not sure I can even remove the motor assembly if necessary.  Any suggestions?

Answer
  Mike, you should observe a small brass collar at the top of the base and below the nut. Be careful. This is attached (part of) a 1.5-2 inch sleeve that is corroded into the base. Spray the crap out of it and gently extract it. You will need to reuse it! It holds the very base of the antenna in when fully extended. Some mast kits come with the sleeve, but not usually the ones available to the general public? Pulling the body doesn't generally help. It's easier to work on when the car is holding it for you.

Mark