Once the SSL you have purchased is installed, simply upload files and pages as you normally would.
If your site was http://www.exelwebs.com, to use the SSL you would add a "s" to the http. The link would now become https://www.exelwebs.com.
You could also change your htaccess code to forse all pages on your website to use https
You can get an example on our mod_rewite example article