I put a piece of two-by-four, (2"x4") about 10-inches long on edge under the door to support the door. I removed the 3-bolts attaching the door hinge at the bottom corner. I then slid the washer onto the post and placed the bracket back in place with the 3-bolts.
That did the trick.
I used a 3/8-inch socket with extension and a ratchet.