Seized Fuel Tank Breather Connector

I’m trying to disconnect the fuel tank breather tube connector from a 1999 Plymouth Voyager 3.8L van. It is all seized with rust. I’m thinking ordinarily I would use a release tool like those plastic inserts used to disconnect the fuel line fittings near the fuel injector rail on my Buick 3.1L engines.Is it best to just cut this fitting out and splice the 2 sections of fuel tank breather pipings together with rubber hose and hose clamps?

if its so rusted that it may break and you are certain that its just a breather line and not a pressure line i dont see a problem with using hose. Just make sure you get a fuel type hose, other hoses are short lived with fuel vapors running through them. just be sure its not the pressure line, if its that rusted you may need to figure something out before it starts a fire.

Would you be able to post a photo of the situation?

I recently had the same situation with rusted fittings on a 1997 Taho.
I had the tank out and was able to tip it on it’s side and spray some PB Blaster into the fitting and let it soak overnight. The next afternoon, they both came right off.