You can edit it only in source code, but you will not be able to keep that after theme update.
That doesn't make sense.. I don't want to make such bold claims if items are over $100. I'll just change it within the code/
</div>
<div class="bp-text-right">
<h3 class="bp-info__h3 pull-left"><?php _e( 'Buyer Protection', 'ami3' ) ?></h3>
<ul class="bp-info-list">
<li class="bp-info-item">
<strong><?php _e( "Full Refund", 'ami3' ) ?></strong>
<?php _e( "if you don't receive your order.", 'ami3' ) ?>
</li>
<li class="bp-info-item">
<strong><?php _e( 'Refund & Keep', 'ami3' ) ?></strong>
<?php _e( 'items, if not as described.', 'ami3' ) ?>
</li>
</ul>
</div>
</div>