What was upgraded:

1. CPU - The original AMD FX-8120 has been upgraded to the AMD FX-8370E.
2. RAM - Two 4GB DIMMs were replaced with two G.Skill RipjawsX 8GB DIMMs, which increased the total memory to 24GB.
3. Power Suppy - The Ultra 700W unit was replaced with the Corsair RM750 fully modular unit, which basically cleaned up the look inside.

The Process:

There were several things that were needed in order to complete this phase of my project.  Obviously, I needed the new components and a clean, well-lit workspace.  The tools used were a #2 Phillips (just for the power supply), canned air (for cleaning up), and some alcohol swaps (for removing the old thermal grease).

1. I cleaned off my workbench/desk, making sure I had plenty of workspace available so there was no danger of accidently knocking anything (especially screws) to the floor.
2. Powered down the Main PC, disconnected all the external cables, and brought it to the work area
3. Cleaned up the outside before opening it up.
4. Uninstalled the power supply which was a little more time consuming than with older systems that did not have options for routing behind the motherboard tray.
5. Removed the CPU Cooler.  In this case, it is the Corsair H100 Liquid Cooler.
6. Used the alcohol swaps to clean the thermal grease from the processor and heatsink
7. Having kept the box/tray the FX8120 came in, carefully removed the processor from the motherboard and put it back in the box.
8. Removed RAM from slots 1 and 2.
9. Used canned air to clean up the insides more.
10. Installed the FX8370E processor, but at this point, did not apply thermal grease or mount the cooler's heatsink.
11. Installed the memory upgrade.
12. Applied fresh thermal grease to the new processor and gently reinstalled the H100 heatsink
13. Now came the most time intensive portion - installing the new power supply and its cables.

Issues:

There were only a few issues encountered during this upgrade.  All of them minor, and one could classified as clumsiness on my part.

1. Had to use a second 4-pin Molex set of cables in order to supply power to my USB 3 PCIe card as the cable by the drive bays couldn't also reach the back of the case.
2. Closing the right-side panel (behind the motherboard) was a little more difficult with the new cables adding bulk there.
3. The cable for the power switch was knocked off the header on the motherboard, so when first trying to power the computer up, nothing happened.  The cable was easily reconnected and the system powered up with out issue.

What Does Windows Experience Index say?

The "cheap benchmark" that Windows has isn't very helpful as it's too limited and honestly, it needs better explanations for its scores.

With that said, the overall WEI rating of the system remains 7.5.

Prior to the upgrade, the primary hard drive, processor, and memory were individually rated at 7.5.  Post upgrade the processor and memory have increased to 7.6, while the drive remains at 7.5

But as I mentioned, I have noticed an improvement in the performance, and that is the important part.  If there had been no change, this would have been a waste.