Update.
Tried wriggling the fan loose last night, did not work. Tapped on it, banged on it with a rubber mallet, banged on it with a piece of wood and small sledge, tried prying between the shaft and fan housing, tried tapping it from behind, no loosening anywhere. So it looks like on to plan B, cutting around the air guide. Was trying to avoid this, but it looks unavoidable.
Now I just have to find my dremel tool after moving, it is still in box somewhere...
Any other suggestions are welcome!
Craig