Hey @User_NA-2642f094,
unfortunatly there is no option to replace the images. That is not a bug but a security precaution for us. Imagine you upload a harmless design and we check and approve it for publication and lateron you replace it with a very critical design which wont be checked again because it originally already was…
Thatswhy there is no other way than to upload your new design again and publish it the same way you already did the first time. But there is a feature that surely could help you: You could use the template feature to save your productselection of the already existing design with all the productcolors, designposition and scaling and just apply it to the new uploaded design. That would save a lot of time.
You will find some information how to do it here: