Hi Geoff, I'm glad you're continuing to update!
To change your original attachment, simply edit your original post and point the attachment to your new file. It will automatically overwrite the old one with the new one.
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Frank Taylor - Author of
Google Earth Blog All about Google Earth news, features, tips, technologies, and applications. Also read:
http://TahinaExpedition.com(If you have story ideas, please send me a private message.)