You could try heating (CAREFULLY) in hot to boiling water and gently straighten the ends. You could also, if the upper hull has any kind of interior bracing or waterline plate, assemble the parts and clamp if necessary, and screw the unit to the base you want to place it on. Alternatively, if there is no waterline plate, you could buy 1 mm thick sheet plastic (Evergreen) and cut a piece to fit, using the upper hull parts as a template. It will have to remain like that for the entire build. You could also contact Dragon Help and see if they will replace the warped parts. If you haven't started any construction yet, maybe the store you purchased it from will replace the kit. It's too bad, Dragon, so far, makes the best 1/700 Bismarck, but Flyhawk has announced one for maybe sometime later this year.