The CB Gallery plugin is a Community Builder plugin and needs to be installed using the Community Builder Plugin Management page.

The installation process steps are:

1. Access the CB Plugin Management page from administration panel using the menu:
   Community Builder --> Plugin Management --> Install New Plugin
2. From the Upload Package File tab click the Browse button
3. Select the CB Gallery package you downloaded
4. Click on the Upload & Install button
5. You should now see a CB Gallery row in your Community Builder Plugin Management page
   and you should also see a new Tab in your Community Builder Tab Management page.

When you install CB Gallery for the first time on your CB 2.0.6+ website it will automatically detect and migrate all CB Profile Gallery items that finds. This way your user uploads will remain intact in this new super-clean environment.