add details to shipping and payment methods

i'm trying to add details to the payment and shipping methods, so my customers can view what each is all about. but i'm having some sirous trouble.

i'm looking at the files in includes /languages /english/modules

trying to add details to payment mods nd shipping mods but it's not working out at all, i just want the extra info to be displayed in the checkout under each method.

payment mods
certapay works
money order works
cod doesn't work

shipping mods
store pickup not working
didn't try any others

the details would show on the order confirmation page (step3 of the checkout process)

for example money order module shows this information at confirmation:

Please make your certified check or money order payable to:
Gorilla Fight Gear

Mail your payment to:
270 George Marshall Way
Winnipeg, Manitoba (CANADA)
R2C 5E2

Your order will not ship until we receive payment.

  define('MODULE_PAYMENT_MONEYORDER_TEXT_TITLE', 'Money Order<br/><font color="#FF0000" size="1">International Money Orders, western Union, Certified Check, or Bank Draft</font>');
  define('MODULE_PAYMENT_MONEYORDER_TEXT_DESCRIPTION', 'Please make your certified check or money order payable to:<br />' . MODULE_PAYMENT_MONEYORDER_PAYTO . '<br /><br />Mail your payment to:<br />' . nl2br(STORE_NAME_ADDRESS) . '<br /><br />' . 'Your order will not ship until we receive payment.');
  define('MODULE_PAYMENT_MONEYORDER_TEXT_EMAIL_FOOTER', "Please make your check or money order payable to:" . "\n\n" . MODULE_PAYMENT_MONEYORDER_PAYTO . "\n\nMail your payment to:\n" . STORE_NAME_ADDRESS . "\n\n" . 'Your order will not ship until we receive payment.');

i tried added these 2 lines to the COD code in includes/languages/modules/payment/

define('MODULE_PAYMENT_COD_TEXT_TITLE', 'Cash on Delivery');
  define('MODULE_PAYMENT_COD_TEXT_DESCRIPTION', 'COD option can only be used for canada post, courier, and pick-up shipping methods');
  define('MODULE_PAYMENT_COD_TEXT_EMAIL_FOOTER', 'COD option can only be used for canada post, courier, and pick-up shipping methods');

nothing changes only the text title is displayed? any ideas as i'd like to add details to COD a few other modules but can't