Modifying the 'Payment Method' section.

[TriumphShop]

Hi,
ZenCart 1.3.8a
I'm in the process of setting up a store with PayPal UK as the payment method. All is going pretty well. The payment system seems to work fine.
We're offering payment by PayPal Website Payments Standard and PayPal Express Checkout.
When a customer gets to the page 'Payment Method - Step 2', there is a box entitled 'Payment Method' and two radio buttons are displayed (see attached pic).
If the first method is selected, the customer is diverted to PayPal's payment pages where the option is given to either pay with your PayPal account or pay via a credit card (i.e. it is possible to pay if you don't have a PayPal account).
The second option diverts the customer to a very similar page but without the ability to pay without a PayPal account.
To me, the two descriptions on these radio buttons are confusing to the customer, because they don't really describe what is going to happen, whichever one they choose.
I would rather either change the descriptions for something more meaningful or simply remove the second option (or have no options at all).
Where do I edit this information?
Thanks very much for any help. I did do a search on the forum but couldn't find an answer.