Gas tank replacement ????

Ok, so I just went ahead and ordered a new gas tank, sending unit, and rebuilt carter carb for the 65 valiant 225 /6. I have a question about removing the tank. I looked last night and took the screws out of the filler tube at the fender and also in the gasket/cover in the trunk. Now, does the filler tube just pull out of and insert into the new tank? What's the best way to get the tube out...before or after the tank is removed? any input would be great. I plan on taking the tank out and getting the new lines ready for when the goodies get here. thnx