through the trunk, open trunk, then look where break lights are, on the door of trunk, top, there are several screws across the top, remove them, then you have access to bulbs. My 2005 Amanti has a post card size "door" on both sides inside the trunk, behind the tail lights. Simple wing nut and remove to get access to all bulbs. very easy.
There is an input and output sensor for the Sedona. They are both located on the top of the transmission. Some people have one on top and one on the side nearest the firewall. Here are the steps on how to replace them: http://bigmektek.blogspot.com/2013/05/changing-speed-sensor-in-05-kia-sedona.html