remove the modal size & decrease the size parameter

 Hello,
I redid a wp site with joomla + econa.
I initially defined sizes. I now realize that there is too much (no need for modal) and the size is too big!

a) remove the modal size
Will this delete all matching photos?

b) decrease the size parameter (ex. 1200px -> 800px)
Will this resize all corresponding photos to the correct size?

If not, if it is not possible, do you have a suggestion, an extension that could do that?

Regards

HI,
Ok I understand I will find out if there is a somewhat simple solution.
Now I will see to manually remove the images for modal.
For resizing, I have to delete it too? or open / save the article with the image econa can modify the dimension?
I imagine that the demand is low but to all hasaer I suggest a tool part, in the plugin, to deal with this kind of problem
Regards