How do I select and delete images in Numbers?

Hi,

I need to delete some images in a previous saved numbers spreadsheet.

I cannot select any image individually, if I click on one cell all images are un-selected automatically.

After pressing ESC and then Cmd+A I'm able to select all images in the spreadsheet but I don´t know

how can I select an image and delete it?

This simple process is getting really frustrating.

Any help/hint is welcome!

Thanks in advance.