Help SSL certificate error, site going live tomorrow!

Hi, I had my web hosting company put a positive SSL on my shop website, I didn’t realize that it would have issues with the images and show as unsecured. I changed the url in WP General Settings. I also changed the wp-config and added the define lines. But that didn’t help. So, then they did something in the .htaccess file (accrdoing to this http://ithemes.com/codex/page/Fix_Non-SSL_Elements_on_SSL_Page#Solution_.232). But that didn’t help. So then they told me to put the Fix SSL/Non-SSL Links plugin, but that didn’t help. So they said it could be my cart plugin, I have woocommerce on this site, I selected the box that says… Force secure checkout Force SSL (HTTPS) on the checkout pages (an SSL Certificate is required). But htat didn’t help. So now I think maybe I should just have the SSL on only certain pages, but I don’t know how. They sent me this. http://stackoverflow.com/questions/9899258/htaccess-https-redirect-for-a-single-page-using-relative-urls

But I don’t know what to follow because there’s two things and I don’t know if it will help either. Any help please? I don’t know how to fix this and the site is supposed to launch tomorrow. I need clear instructions that will work to follow. Can someone walk me through this please? But I need to have it fixed by tomorrow.