ok if you have a new speedo and you get a new cable, this is a very easy thing to do. there is 4 nuts holding the insrument to the dash the bolts are attached to the dash, unscrew them and pull back on the speedo. it will come right out. disconnect the cables that run to the fuel and water and be sure to mark them accordingly. unscrew the speedo cable and then carefully pull the lights from the cluster. be sure to mark which hole they came from mainly for your break light and 4wd indicator....to put it in just reconnect everything...
As for the Speedo cable its relativly easy...unscrew both ends (speedo will already be done and from the transfer case)...you cant miss where it screws into....the hardest part will be pulling it from where its secured to the vehicle, and running the new one... If I had to rate this for difficulty, id say easy.... you shouldnt have any problems....just make sure your cat converter is cool cause on mine the speedo cable runs above it and can burn ya... good luck..
81 Jeep CJ5 4" lift, 33" Mickey Thompson Baja Claw tires.