There is no seal on the Hub when you pop off the top.
and
It is very easy to do.
On all my hubs I have look inside and even swapped out HDD.
but
Even if I were to buy a 2TB Hub I would open it up to see what is inside.
On my first Hub
I held off on my purchase until someone posted pictures on insides of the Hub.
Some of us
Like knowing what we are buying.