~3 hours and it's done! Everything smells like gasoline now. The most difficult part was getting the fuel fill hose clamp (green area) loosened due to the tight space and angles. After a bit, I realized that the tank had shifted forward a few inches... making it nearly impossible to get the socket in there. A quick shift backwards and then off to the races. If you didn't relieve the fuel line pressure, I'd strongly recommend having a rag ready for when you take off the fuel line quick-connect fitting.
I used a open ended crescent wrench and a hammer on the the lock ring. Turn the wrench sideways and slide one of the sides into the smaller holes on the outside of the ring and give it a few taps.
If I had to do it again, it should only take 30 minutes.