Speedo cable swap.....how hard and how to do..

OK, my speedo cable melted to one of my header tubes, i have a 460 so its pretty tight in there and i didn't notice it till last night. I removed the speedo gear from the tranny and noticed how hard it was to spin, then i swa the melted part, tried to free it with my drill but that just twisted the cable right off the end. How hard is it to swap in a new cable, and can i use the cable from a 4 cyl. fox? AOD and C6 tranny gears are same so thats not an issue.
 
If the outside casing on the cable is still in ok condition you can go to autozone and get a replacement cable. You only need the outside casing if you do it this way. Only like 8 bucks I think. Easiest way to do it.
 
I remember when i took my instrument cluster out and to pull out all the way you have to disconnect the speedo cable and i did, it took me at least an hour to get that spline lined up and back in, i couldnt believe it where one day i had done it in less than 30 seconds. Once that is out just yank it out from the firewall (from engine bay i mean) (i think) then disconnect it from the trans (1 bolt) and pull that out and should be ready to swap in the new one in after you swap over your existing gear that goes in the trans and put it on ur new cable. I dont no about the 4 cyls. A new cable from advance is around 17 bucks and i think from ford its like 30 bucks. I would just get a new one.