I long ago converted my pre-AI lens. It's very easy, since the only problem is the depth of the skirt. Since it does not rotate or engage anything all you can just turn it down or file it or put the ring on a piece of sandpaper and sand it down a little. If you don't care about appearance or are in a hurry to see how it works, you can even just leave it off and put the mount back together. It's just a trim piece.
I've long used mine as a normal lens on DX. Not a quick off-the-hip shooter, but it doesn't take long to get used to guessing the exposure on a non-metering camera like the D3200, and it meters fine on a D7100. Mine is sharp and renders colors and whatnot very nicely, and the ability to shift yourself out of reflections is very handy indeed.
