My Olympus OM-1MD 35mm camera's mirror is out of focus w/ 3 mirrors, how do I fix this myself?

I was cleaning it, and I went a little OCD, but then the film gate (I think, the little black square from above the mirror) fell out and using a q-tip, i placed it back, only to discover my aperture was so out of focus and resembled a fisheye lens. How can I fix this? I know it's old, but I can't find any help on the internet and I don't have a manual myself. Thanks.