Thanks. I've tried copying and pasting with right click on the mouse, with Cmd C and Cmd V, with single click on the icon then using the Finder Edit menu to copy and paste and also dragging and dropping.
The first three do absolutely nothing. Drag and Drop gives the usual Green circle and + sign when over the existing Get Info icon as if, for example, you were dragging a document into a Calendar appointment, but the "paste" doesn't take place.
I've tried it with a png file (303KB), which is the file to which the article points and also as a jpg file (86KB) which I converted using Preview.
The icon refuses to change!
