its just the diameter thats different.
you can buy or rent the double flair tool. sears sells a good one for like 50 bucks irrc. harbor freight has a 20 dollar one, but it may not cut it on the larger firmer lines. may need a tube bender too. but those are cheap.
the words i cant do that should not be said. cutting out old lines and replacing them is the norm for a older car.