This is a very simple thing to do open your page save page as with the new name then republish it all your links will still be working unless those pages with the links goes back to the old pages with the old names then you got to do all those links over. then theres one more thing to do in cpanel is to delete the pages with the old names.
If those old pages have rankings I myself would leave it as , because when you do a new page it will like be starting over with the search engines. The search engines may ban you if you do with the old and new it will be like spamming
Joe
anytime-figurines.com
jkteddybear.com