At my first attempt to fabricate custom window screens, I inadvertently cut a couple of cross bars about 1/8" too short. Make frame bowed at center and not fit the opening.

Is there any way to replace them with the right length? Are they flexible enough to slip out of the clips?
Any tip or tricks will be welcome.

 

Generally the spline and screen have to come out because the crossbar end clips are rolled in underneath the spline. And you can't spread the frame while the screen is rolled in.

 

You will need to buy a new cross bar and new screen. To properly measure the cross bar use the inside dimension of end of the screen where the corners meet. When you install the new screen you don't want to pull the screen to tight. Using the spline tool's groove side, hold the screen with one hand on the inside of the screen and groove the screen with the tool letting it pull the screen from the outside of frame. Install the spline. Do the next adjoining side. When you get to an opposite side of an already splined side, again just pull the screen taught, not tight, Let the groove side of the spline tool provide the proper tension. When your done if the screen twists, it's too tight. A little bit of slack in the screen is OK.