Mycow80

Hey everyone. I'm thinking of getting the pioneer AVHX 4600BT for my 2004 Kia optima EX. It has the infinity sound system and the automatic temperature control. Does anyone know how difficult the install will be for this unit? I'm wondering if I will need to do anything with the existing wires or purchase an adapter? Or can I just plug the existing wiring right into the Pioneer head unit? Also, are there any online instructions for how to install this unit on my specific car? Thanks!