Help - how do I put back window screens in window?

[Moe Hair]

I have window screens which slide up and down (most do, of course). I took out two screens which were torn so I could repair them. I was able to push one side of the screen against it's slot and then pull the other side out. My problem is how do I get them back in!? I've tried to slide them in, but I can't get one side past the window frame. Is there a secret?

[JohnB]

My screens need to be "twisted" [one side in before the other]. Of course I don't know how yours work.

[Childfree Scott]

I need to use 2 flat head screwdrivers to gently pry mine in. And yes it's very difficult to do!