Remove the subscribe button on the payment page

I am using Membership Premium (Membership Pro?) 3.5.2.5, but I can only choose Membership 2 Pro when filling in this form.

http://www.stopovereating.co.uk/payment/?action=subscriptionsignup&subscription=3

After creating an account, users are presented with two payment options:
- Subscribe / Auto Renews
- Pay Now / Does not Auto Renew

On this page, I want to remove the subscribe button completely, and just have the pay now button. May I know how to do that?

Thanks!