To clarify, you can use a NEW piece of wire and add an in-line fuse rated at 80-100A. I've seen some repairs made with car audio amplifier power wire (4Ga.) and and amplifier in-line fuse that work perfectly well. Do not add an in-line fuse to a fusible link wire.
As BigMike stated, you'll have to disassemble the fuse box to get to the terminal inside where the fusible link wire attaches. I believe it is attached via a ring terminal to a stud with a 8 or 10mm nut on it. The correct way is to make up a new fusible link wire, but if you can't find one easily, you can go the inline fuse method.
Secondly, you need to find the cause of the damage to your fusible link. Generally, they don't just "go bad". Something caused it to overheat and short (wrench from alternator + term to the frame, jumper cables hooked up backwards, battery terminals hooked up backwards, etc.) Sometimes they just go bad due to the corrosion from the battery terminals. At any rate, be sure to correct the cause of the failure before proceeding.
FWIW, you can get very very nice battery terminal ends at the dealership, instead of the stupid crimp-style terminals they sell at auto parts stores. They have a stud on them to attach cables to (by using ring terminals on the cable ends), and a 10mm nut that tightens them around the battery post. Also, they loosen up nicely for removal, compared to the stupid cast lead ones at the parts stores...
Ryan
