replacing electric antenna motor drive

[ellismks33]

Hi

Anybody know how to replace or fix electric antenna motor drive........

My electric antenna motor won't turn off. The toothed cable has snapped off.So the motor just keeps on turning. I have to remove the fuse to turn it off. Can't see a way of getting to the motor drive to push through new toothed cable. I have tried to push it from above ,after undoing the nut screw and taking off the rubber covering .So find it hard to connect toothed cable with motor from above and motor won't turn off. Any suggestions would be very grateful. Thanks