Start off with an 18" funnel. Look just behind the engine below the battery and you'll find the speedometer cable coming up from the transmission. It's attached to the drive which is secured to the transmission by a bolt with a 10mm head. Use a socket, extension and ratchet to remove it. You want to remove the drive from the transmission with the cable attached. It will probably be stuck so will take some fiddling. Use a flashlight to look down into the hole and you want the speedometer drive gear covered in tranny fluid. If needed fill with Pennzoil Sycromesh or 75W90 gear oil. Sorry don't have any pictures.
Hope this helps, Jack