Replacing the cable is the same as replacing a speedometer cable. I would start by taking only one end off and then grabbing the inner cable with a pair of pliers and pulling it out. Once out of the sheath, run the cable through a piece of cotton tee-shirt material and see if there are any broken wires that are causing the problem. If there are, you can purchase a new cable that will have an end that gets crimped on with the tool that comes with the cable. Use the old cable to get the exact length. If the old cable is broken, then you need to take both ends off and hopefully, you will be able to grab the broken end with a pair of pliers. If not, then you use the new cable to push the old one out. The cables come in various lengths, so take a measurement of the old sheath and add some extra for the new cable. Lubricate the new cable with a very thin coating of white lithium grease. Insert and when it bottoms out at the other end, you will need to turn the cable to get it to engage.
