Fica aqui o link para estudar quando tiver algum tempo….

http://www.joomlapt.com/dificil-atualizar-sem-megaupload.html

http://forum.joomlapt.com/faq-j2-5/10234-migrar-1-5-para-2-5-a.html

http://cmsteachings.com/how-migrate-joomla15-joomla25-part1

http://cmsteachings.com/how-migrate-joomla15-joomla25-part2