There is more than one method. The simplest is the refresh method which you add to the <HEAD> </HEAD> section of your old pages (recreate them if they've been deleted as follows):
Don't make the value less than 10 seconds!
<META HTTP-EQUIV="REFRESH" CONTENT="10; URL=http://www.yourdomain.com/newpage.html">
<TITLE>This page has moved</TITLE>
This Page Has Moved
Please update your bookmarks to
Alternatively, if your host allows an .htaccess file, you can use a 301 redirect there:
Or, if you can use PHP:
Or, if you're on a Windows server, use ASP:
header("HTTP/1.1 301 Moved Permanently");
response.Status = "301 Moved Permanently"
response.addheader "location", "http://www.newdomain.com/page.html"