The exposure reading was taken from the brightest part of the sky so the clouds didn't become washed out.
The photo was then imported into PaintShop Pro Photo X2 and the ReDynaMix plugin used to bring out some detail in the shadows. This was followed by the use of a plugin called Wire Worm which can be very effective at sliding and blending nearby material over the unwanted parts.
If you are interested in Wire Worm then have a look HERE at MV's PLUGINS. It should work with any graphics program which recognises Photoshop type plugins.There are some excellent examples of its use and a short video demonstration of its facilities. The best part is - it's free.