Well go to your nearest auto parts store, tell them what you need.
disconnect the black (negative) cable from the negative battery terminal, then take the red (positive) cable off of the positive battery terminal.
now you can disconnect the other ends. The black cable is most likely connected to the engine or the frame. and the positive red cable should be connected to the starter solenoid. Just either follow the positive cable, or check your owners manual to see where it goes if you want to be safe.
put them back on the opposite way you took them off, reattach the end of the new positive cable to the starter solenoid, and the new black to the engine or whereever it was connected. If yo uwant good protection put corrosion inhibitor (petroleum jelly will do fine) to the threads on the bolts. Then apply the corrosion inhibitor or jelly to the positive battery terminal and then reattach the positive cable.
Then put the negative cable back on, apply corrosion inhibitor to the negative battery terminal, then place the negative cable on the negative terminal on the battery. Don't tighten it too much or you'll break the cable ends. Then you should be good.
Sorry, I thought you wanted to know if you need new ones or if the old ones clould be fixed.
As for how much, if you are a factory fit fan you could go to the dealer and get the battery cable kit ( positive and negative cables) for $ $135. Or just go aftermarket for about $ 10 a cable. And here's alittle how-to:
When disconnecting the battery cables from the battery it is important to remove the cables in a particular order to minimize the chance of personal injury and component damage. The negative - battery cable should be removed first to stop the body of the car from being an active ground. After the negative cable is removed and set aside, the positive cable can be removed from the battery. The cables, once removed, can be cleaned with a solution of water and baking soda to remove any corrosion.
If the positive (+) battery cable is disconnected first, the chance of grounding the positive terminal against the negatively charged car body with a wrench or other metal tool is much greater. If the battery is so grounded, the battery, alternator, PCM or other fragile electronic components may be damaged by electrical surges, or any flammable gases may be ignited by the sparks produced by the electrical arcing, leading to possible fatal personal injury.
The battery cables should also not be disconnected with the ignition in the ON position. The sudden removal of the electric current can cause numerous electrical surges throughout the electrical system. These surges can damage any of the various voltage sensitive components such as the PCM. Always make certain that the ignition switch is turned OFF.
Make sure the ignition switch is OFF.
Use the appropriate size wrench(es) to loosen the hardware on the cable clamps. ALWAYS begin with the negative battery cable.
If necessary, use a puller tool designed for battery cable clamps and remove the clamp, then isolate it from the battery terminal.
Remove the positive battery cable, if required, once the negative battery cable has been removed.
Clean the terminal ends with a solution of water and baking soda to remove any corrosion.
Place the positive battery cable onto the battery post. Make sure the clamp is flush with the top of the post.
Tighten the clamp nuts to 75 inch lbs. (8 Nm).
Repeat the procedure for the negative battery cable.
Double check the battery clamps are secure.
Start the engine and take the vehicle for a short ride about 15 minutes to be sure the battery is charging correctly.
I had to replace the positive cable on my 3.3 a couple of years ago and it is not a simple 20 minute fix. You will be working in some very tight spots with fasteners and stuff that are just plain frustrating to try to get a wrench on. Give yourself some time if you're going to tackle this job!