skin/customer/main/checkout.tpl
look for ..
<p align="center">{$lng.txt_you_are_agree}<br> <A href="help.php?section=conditions" target="_blank">"{$lng.lbl_terms_n_conditions}"</A> {$lng.lbl_and} <A href="help.php?section=business" target="_blank">"{$lng.lbl_privacy_statement}"</A>.
not sure if its the same for version 3 though
hope that helps