For the speedo cable, just remove the left vent, push the duct down, squeeze your hand back, and unscrewcthe cable from the cluster. Pull the cluster out a bit, but once you feel the speedo cable resisting stop and don't pull further. If you absolutely can't ram your arm far enough in, you'll have to undo the speedo cable at the trans to give you more slack. Your arm will be sore and cut up, it's normal.
