amongst the numerous emails you will of had from surpass one will have their nameservers ns.---------- and ns.---------- WHEN you site is up and ready go to your domain agaent and look for DNS /nameservers setup or whatever. Assuming your XOOPS site is installed in the root of your webspace, enter both ns numbers in the appropriate forms. They may also ask for your ip or web address as well. Now allow 24-48 hours for the DNS to propagate. Your temporary address of "http://xx.xxx.xx.xxx/~username" will be changed for your domain name.
If you want to get XOOPS installed easily go to your cpanel and look for scripta icon (a penguin) click this and you will find XOOPS listed.
Richard