WP e-commerce-Couple of questions

Two quick things with customising WP e-commerce if anyone knows.

How would I change the text in your shopping cart when it’s empty, so that the button says something instead of “visit the shop”.

Secondly, when customers go to checkout, once they have typed in their billing and delivery details, there is then a button at the bottom that says make purchase or something. This then takes them to Paypal to pay. How do I change the wording on that button?

Many thanks for any help, I really appreciate it.