Chosen Solution
Is there a step by step procedure to do this? (change out the CPU’s to new 8 core)?
Here is Apple Service Source manual. Page #68 begins the process. I have done this a couple of times. It is a moderate difficulty upgrade and well worth doing, especially if upgrading from a single CPU. This is not the guide I used, I will see if I can find one easier to use and post later. http://tim.id.au/laptops/apple/macpro/ma… Star at step # 34m of this guide: Replacing/Upgrading Mac Pro Processors (Early 2008)
