You split your website traffic between these two versions and measure their performance using metrics that you care about (conversion rate, sales, bounce rate, etc). In the end, you select the version that performs best. 

I'm going to encourage you a little, to help you get started. :)

I am going to encourage you a little, to help you get started :)
Since you looked us up and read the site enthousiastically, I would like to offer you a big discount.