i have not done it on a stang, but i usually like to unbolt the block and get at the back side. one can usually use a dental pick or tiny screwdriver to press the pin on the wire and pull it out. if you get some OEM style terminals, you should be able to put the new terminal back in the same way (which is imperative, since the fuse blade will try to push the terminal out the back, which could get to be real old).
in a pinch, i have bypassed bad connectors with a splice and inline fuse of the correct rating.
good luck.