upgrade from Version: 2.6.2 to 3.0

Yup. You actually have to upgrade them all to 3.0 if you plan to upgrade any. 3.0 and 2.0 extensions aren't compatible with each other.

For the Invite and Login modules, you'll loose your settings. Sorry. For the component, your current settings with 2.6.x will stick, but you'll want to go through the settings again as there's a lot of new options.

Hope this helps. If you have any other questions, let us know.