IVR Installation on 65 Dart Cluster

I need help with a project which I am completely unqualified for. My gas gauge and temp gauge are dead so about three years ago I purchased a new IVR from RTE (redfish) to fix it, but never had the courage to undertake removing the dash cluster. I now have a shiny new cluster to install so I'm going to try to tackle it. I am totally unfamiliar with electronics or anything electrical. The photo below shows what I received from RTE but I don't understand any of it. I need someone to describe what I need to do to install the two parts I purchased, preferably with pictures showing what get's soldered or plugged into what. I am hoping one of you will try to walk me through it. Thanks in advance.

IVR.jpg