Hi Kenneth,
So do you have an easement for that area? If so, what are the terms of the easement?
If you have the right to enter and exit, then yes, you could open your fence so that you can enter and exit as set out in the easement.
It might be worthwhile to give your neighbours the heads up that you're going to do so (in accordance with your rights under the easement) so that you keep on good terms.
You might also find the Land & Property Information NSW
"Easements and restrictions" page informative.