Help me turn my reef into an octo tank

I have a 30 gallon reef tank with all the fish moved to my upgrade. and i am going to put an octo in there, how do i seal the top to the tubes going in and out of the tank for the filter, the heater, and protien skimmer witch i might take out because it looks impossible to make it octo proofwith it in because there space behind it. How would i make this tank "octo escape proof"?