Aye, I guess you can to a certain extent.
Since the theme is delivered as a
Creative Commons License you should give credit to the author somewhere on your website, and if you want to redistribute it further it should be a also licensed under a CCL.
At least that is my understanding of CCL which applies to the theme.
From what I understood GL does not require you to show of a link to Geeklog, so you may remove that one.
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