Switch WP domain with ipage

Hi,

I have the domain dockworthy.com and an old site built for it through ipage.com. I have built a new site with WP and the domain we have used is dockworthy.com/temp. I was wondering if anyone could point me in the right direction how to switch the dockworthy.com domain over to the wordpress site without starting over. Last time I tried, I almost lost the site.

Thanks!