Australian fern tree (too tall)

I'm not sure if I can help but I guess it would depend on the type of tree fern it is.
Is it in the ground or in a pot?
It would be helpful if you reposted your question with a couple of photos.
Sorry I can't be of more help.

Depends which tree fern you've got - if its Dicksonia antarctica, yes, you can saw it through and replant the top, but if its Cyathea australis, you can't. More info in the link below

http://www.abc.net.au/gardening/stories/s2993205.htm

Bamboo to the rescue ^_-