1. Navigate to your Office 365 admin center by clicking the tiles and then the "Admin"-Button.
2. In the Office 365 admin center first click "Show all" in the left side navigation and then click the button called „SharePoint“.
3. Click the button in the left navigation called “apps”.
4. Click the hyperlink called “App Catalog”.
5. If you don’t have an existing App Catalog Site, please create a new one. Just click the OK-Button.
6. Give the App Catalog Site a title, url, select a language, add an administrator account and set the storage quota. After the configuration click the OK-Button.
7. Wait until the site has been created.
8. After the creation is completed, click the button called apps in the left navigation.
9. Click the hyperlink called “App Catalog”.
10. Click the button called “Apps for SharePoint” in the left navigation.
11. Select the Collaboration Manager 365 App file on your computer with the name “CM365.app”.
12. Drag & Drop the app file “CM365.app” to the SharePoint app library.
13. Wait until the upload is completed and check the parameter below.
14. The app is now ready to be installed in SharePoint.