RV Repair: replacing front ceiling panel-86 Play Mor 13 trailer, birch plywood, going in the right direction

Question
The front ceiling panel on my little travel trailer obviously got wet and delaminated. The white vinyl is sagging greatly. I have sealed all leaks and 97 inches of snow throughout the winter has not leaked through. I have bought a piece of 1/4 inch birch plywood that I will stain to match the rest of the wood in the trailer. How do I get that curved bend from over the perpendicular front window to about a 30 degree ceiling.  Nerf cuts on the back?  How deep can I go without it splitting?  Thanks.

Answer
Ron, you are thinking the right way with putting nerf cuts in the paneling. As far as how deep, well if it is 3 ply I wouldn't go completely through the second layer but just 1/2 way through. I hope that this helped reassure you that you are going in the right direction and remember that it is better to cut twice before going to far the first time.. Take a small piece of the wood if you can and use it as a test piece to find out just how deep you will need to go and no deeper. Thanks, Bill