youll need to tune your A string down so that its 7th fret matches your open G string, 

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-5-5-5-5-5-5-5-5/6b-6b---------|
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-5-5-5-5-5-5-5-5-8/10-8/12-----|
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-5-5-5-5-7-7-7-7-8-8-8-8-10-10-10-12-12-12-15-15-15-17--17-17-17-----|
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--5---5---5---5--6b-6b---------|
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ride around forever on an empty take of gas...