I found it.
Must edit "form-edit.php" and "settings.php".
You can add a line for new currencies, result would be like this:
$paypalcurrencies = array('USD' => 'US Dollars',
'EUR' => 'Euros',
'JPY' => 'Japanese Yen',
'GBP' => 'British Pounds',
'CAD' => 'Canadian Dollars',
'AUD' => 'Australian Dollars' ,
'BRL' => 'Real Brasileiro'
);