When I swapped calibers, I replaced the ejector with a 38 (super) auto ejector, it's easily enough done, as there is a 1/16 dia cross pin retaining it.
You can also get a 9mm slide, recoil spring and barrel and convert to that as well. The 38 auto ejector will work with the 9mm, but the 9mm ejector nose must be shortened a bit for the 38 auto or it will contact the extracting brass too soon.. The 38 auto magazine will feed 9mm, but the 9mm magazine has a spacer in it and won't accept 38 super ammo.
With a slide, recoil spring and barrel and magazine you could also convert to 40 S&W.