As it was mentioned on here I took instructions and thanks to Somersetrebel and Misfixit I set about replacing it
Broken aerial

Removed and aboout to saw off stub at mount

Once cut I drilled out the middle to correct size for brass screw

Then a thread was tapped

once the thread was done Its put together(shows tap and die set and differentsize brass bits

Finaly fit back to bongo with the new bearing I perchased

all works and should now not break so easy and more than a third cheaper than a mazda origonal