Is it "stuck" as in nothing will move it? Or is it just very "tight" and way harder to move than it should be?
I ask because one of my Omegas (don't remember which one now) was so hard to move it took two thumbs to move it at first. I sat here watching TV and forcing the safety back and forth till my thumb got tired, switched to the other thumb, worked till it got tired, went back to the other thumb, worked till it got tired and then worked the safety with my fingers back and forth.
It got easier the more I worked it and finally got to what I felt was acceptable. I'd oil that post/flat piece/detent and spring up before doing that.
No idea why that one pistol was tougher than the others, but it's been "normal" for the years since I broke it in that day watching TV.