Great Job. Patience is the key. Cutting that overhang is the 2nd key. In your scenario 8" is a lot to gain. I would also complete the grading. Getting out boards is too cumbersome each time. Pouring concrete would be a one time deal.
Great video it really shows the challenge you face, however as part of the effort it took to make the video I would have put the same effort correcting the grading and eliminating the overhang.
The video does allow you to share your dilemma with others however it does nothing to eliminate the problems.
Concrete or gravel and a circular saw would go a long way towards making backing in a lot easier
