making a secondary image the main one on a title

I have been reading the instructions and trying to edit the main profile image of o film title of mine (Um Filme Falado) and have not found the way to do it. Neither on IMDb traditional site nor on IMDbPro and not even on my iphone. I am a Mac user. It should be simpler. I can't edit as instructed on IMDbpro. I have really looked for all possibilities. Could you please help?It's simply asking for an image I already have as secondary to become the main image instead of the current one that doesn't show any face due to composition.

I look forward to hearing from you soon.

Best,David Bonneville