Change a few words?

I just need to change the spelling/workind of a couple of words.

On my payment methods, I have check/money order enabled.

However, I need to change the spelling of "Check" to "Cheque" and the words "Money Order" to "Postal Order", so it says "Cheque/Postal Order".

Does anybody know how to do this?

Use the developers tool kit in the admin > tools area to search for text

I did a search and it pointed me to /includes/modules/payment/moneyorder.php

Went there but I can't seem to change it, I can't find Check/Money Order anywhere.

Can anybody else help?

A search on money order yields this:

/includes/languages/english/modules/payment/moneyorder.php

You will want to change lines 22, 23 and 24, as they all have American spellings.