2. Check the terminals for deformation, the presence of bolts and signs of corrosion. The appearance of white flakes under the insulation near the wire terminals is a sign of corrosion; a wire with such deposits should be replaced.
3. When replacing wires, always disconnect the negative battery cable first and reconnect it last, otherwise the battery may be shorted by the tool used to loosen the terminals. Even if you are replacing only the positive cable, first disconnect the cable from the negative battery terminal.
4. Disconnect the wires to be replaced from the battery terminals, then, having found their opposite ends, disconnect them from the starter and the "ground". To correctly install the new wires, remember the layout of the old wires.
5. If you need to replace one or both wires, take them with you when purchasing new ones to avoid making a mistake in your choice. The wires can be identified quite easily by a number of characteristic features: the positive ones are usually enclosed in red insulation, have a larger cross-section and a larger diameter hole in the terminal that is put on the positive terminal of the battery; negative wires have black insulation, are thinner in cross-section and have a smaller diameter hole in the terminal.
6. Clean the threads on the starter relay contact and ground to remove any traces of corrosion. To prevent corrosion of the contacts, apply a thin layer of battery terminal grease to their threads.
7. Connect the wire to the contact on the starter relay or to ground and tighten the nut securely.
8. Before connecting the new cable to the battery, make sure it reaches the battery terminal without tension.
9. First connect the wire that goes to the positive terminal of the battery, and then the one that goes to the negative.
Information taken from the official website: «ChevyMan»