I'm assuming this is using PayPal Payments Pro?
On the the checkout page, delete the paypal checkout button.
on the confirm page, open the server behaviors panel and remove the Local Checkout server behavior.
you should also have the following server behaviors:
Universal Email
Store Order Summary
Store Order Details
they may be in a different order, which ever is last in the list of these three, double click it and set it to redirect to the checkout success page.