Turn fill screen off, alt-click logo until it is haloed, then click the red button and click repaint. Don't use the text tool though, it won't work.
Offline
or...
get the skin change the 2 logo files then read the skin (I persume you know how) and save image in user mode.
Next turn file off, alt click the scratch window and click the dismiss me button. Finally click, open, Scratch and then your logo should be there.
Offline
I know that should work, but for me, it crashes Scratch. It doesn't like reading anything other than the default skin values. It's weird.
Offline