The starter on a 2002 Kia Rio is locared on the back side of the engine under the intake manifold. Just about the only way to even see it is from underneath. It is fairly small. (About the size of a can of soup) It has two wires going to it. A large battery wire and a smaller connector to engage the starter. Disconnect you battery ground wire before doing anything with the starter.
Raise the front of your Kia off the ground with a jack. Make sure it is high enough to work under, then position a set of jack stands under the front suspension to support the car
Position yourself under the passenger's side of the car and locate the starter on the engine. The Rio has a support bracket under the starter that you need to remove before you can remove the starter.