Legally speaking, you must get a shop to do that. The remaining freon needs to be captured. Plus, after replacing the hose, the system needs to be evacuated before the new freon is added.

In reality, you should be able to get a used one from most any boneyard. Ones from Troopers & Amigos with either a 3.2 or 3.5L should be the same.

I have no idea where to get a new one.