Hello Giulia,

To migrate from Joomla 2.5 to Joomla 3.0, here's the steps that you need to perform.

1. Open up PHPMyAdmin tool that is provided by your hosting provider and open up your current site's database.
2. Make a sql dump for all the tables that has the prefix of #__easyblog_*
3. Download the .sql file and save it on your desktop.
4. If your new site's database prefix also uses #__ , then you can skip this part. However, if you are using a different database prefix, you'll need to edit the .sql file that you've just downloaded, and do a search and replace of #__ with your new database prefix.
5. Open your PHPMyAdmin and this time, open up your new site's database.
6. You should see an import link at the top. Click on that, and click on browse. Select the .sql file and click the run import button.
7. Install the latest EasyBlog on your new site

Hope this helps.