Removing creases from softbox diffuser?

[RJL2005]

Any ideas on how I can remove the creases from my FITP softbox diffusers? The seem to be made of a nylon type material and look like they'd melt easily. Not a problem usually but can be seen in the reflection when doing water drops etc.
Thanks

 

[TheBigYin]

steam them ?

 

[lawrie29]

Wet it, then let it dry open? Apply some steam as it dries?