Today, Joomla is upgraded by copying all the files for the upgrade into the web root of the site. This works fine and there are also some joomla migration scripts that makes this process even faster.
Migrating or upgrading joomla to a completely new version of Joomla is another case. Joomla 1.6 will have a lot of new functions and changes. Not only the files will change but also the structure of the tables, and some files will be deleted. Those things don't happen in a regular Joomla update. Thus, the Joomla migration process is not just about copying files. Normally, the process would be to delete all of the files for 1.5, and then migrate all data, image files and setup into Joomla 1.6. This is not ideal.
The Joomla migration process consists of multiple phases:

• Phase 1: Migrate if needed your Joomla site to Joomla 1.5.15 if below version Joomla 1.5.14 (from Joomla 1.5.15 upwards we can migrate)
• Backup and download your entire site to one of our development servers.
• Get the SQL Migration file.
• Creation of the new Joomla 1.6 site with the SQL-file uploaded to the new Joomla 1.6 directory and install both
• Move all media (images etc) from the Joomla 1.5 site to the new Joomla 1.6 site
• Phase 6: Install all extensions as previous installed in Joomla 1.5.12 (if available in Joomla 1.6 version) and if the components offer no backup/restore for their data, the tables from the old site's database will be copied to the new site's database.
• Move all database tables and possible related images or other extension related media/document/etc files over to the new installation & Testing
• Change the Site to your new migrated site in the Midnight.

If specific extensions are not available we can install replacement extensions with at least similar functionality. These installations will be charged separately and only upon request. If extensions need upgraded before the Joomla migration to make them compatible (for instance CB/VM/etc) we will charge separately for these tasks after reviewing your installed extensions on your present site.
Time to migrate: Minimum 1 week depending on the amount of content evolved.
Upon Purchase you will receive an order confirmation email. Note: We need full access to your ctrl-panel (cpanel/plesk) and super-admin and ftp!