Sawzall
We just cut the inner part of the spindle flush straight down and bolted on the Simmons. We have done 2 sleds like this and works fine. I know of another that used M7 skies and has also had no trouble. Otherwise Simmons used to make mounts for these that are wider but they are hard to find. They are the only ones I know of that made a ski mount wide enough to fit the early AWS spindle.
Good luck