[MBZ] Antenna mast removal

[Mnetzky1]

I know this has been discussed before, and the procedure should be  easy.  I 
can't remove the antenna mast from my 83 300D.  I removed the  notched 
threaded ring, the black gasket, and turned on the radio to  activate the "up" 
antenna.  As the antenna was going up, I pulled on the  mast.  It didn't come 
out.  
I repeated this procedure with the same  result.
 
What am I doing wrong?  Thanks.
 
MikeN