Don't have the mold but I'm assuming rubbery plastic. If so get yourself a mug and some boiled water. Dip each wing tip into the water long enough to heat them up and then re-bend the fins back to a straight angle. Just be careful because you boiled water and all(you'd think this wouldn't be something that needed to be said but you'd be surprised). Just keep repeating until your happy with the results and just let air dry.
I would run it under cold water immediately afterwards to set. If you leave it to air dry the soft plastic tends to slowly bend back to the way it was bent.
When you pour the hot water on them, you’ll see how they want to return to the shape they were molded into. I usually pour the hot water for as many seconds as it needs to become flexible, then put it in a position where gravity is not working against you while I find a way to hold it in position while running it under cold water. You may have to do it more than once, depending how much of a perfectionist you are. Be sure you’ll probably have to do it again in the future.
Good point, hadn't thought of that since I usually see this done with old Kenner SW figures without issue.
Thanks for all the suggestions. Is there a way to hold the tailfin in place, so it would stand upright?
Might be able to wrap a small rubber band around the base. If you’re gonna try to set it under cold water immediately after heating I would just hold the stabilizer by the tip and keep it straight that way.
Not just cold water, bowl of iced water. Pour kettle boiled water over for a couple of seconds at a time until you can re position without excess effort, hold in shape yourself by hand (or clamp straight edges like icecream lolly sticks) , dip in bowl of iced water and job done.