New gauge cluster and mirrors question 09 proStar

I bought a new cluster gauge with white out faces. The only difference is that the new one has engine oil and transmission temperature. My old one did not have these two gauges. My old gauge cluster only had one plug on the back and the new one has two. All of the gauges work except the two new gauges. I wanted to know if it's possible to make these gauges work. I am assuming I will need a wiring harness to go from the engine oil and transmission temperature sending unit to the body controller. Then I will need another wiring harness to go from the body controller to the gauge cluster. Then I assume I will have to turn on these functions using diamond logic in the body controller. There are also several warning lights that are not turned on in the body controller now and I would like to turn on. They're the front and rear axle differential lock as well as the engine brake light. Can these parameters be turned on as well in the body controller?

Also I bought new mirrors that have the chrome backing with the marker light. My old mirrors did not have this backing or marker light. They are factory rejects that I bought for a good price. The one on the passenger side has nothing wrong with it and it works perfectly. The one on the driver side the motor does not work because it was not wired properly. I need to take the backing off of the mirror to expose those wires so I can fix it properly. Does anyone know how to take those backings off the mirrors?

 

Thanks HeavyD. The mirrors sound straight forward. As for the guage cluster are you saying that there should be a plug hanging loose under my dash for the engine oil temperature? And if I can find it and plug it in then I will still need to turn on that parameter in the body controller?