It's very easy

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In your Admincp -> Languages & Phrases -> Phrase Manager ->Add New Phrase
For queries:
Admincp -> Import & Mantanance (all the way at the bottom) -> Execute SQL Query
NOTE: You'll need to set your permitions to execute queries in includes/config.php

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If that doesn't work, just reply, and I'll give detailed instructions (or do it for you, if you want).
It might take a while before I reply, Friday is a very busy day for me