1. Go to the Site Settings of the site and select 'Title, description, and logo' from Look and Feel.
2. Update the Site Title with the new title.
3. Go back to the Site Collection, select Site Contents and click the 'K2 blackpearl for SharePoint' app.
4. Scroll down to the bottom and select Activate Site Collection. This will reactivate the Site with the new title.
5. Next, go to K2 Management and expand Users > SP. Selecting this will show the SharePoint Group Providers.
6. You will notice that a new entry has been added for the Site Collection with the updated Title, but there will also be a duplicate entry with the old title. Delete the Group Provider still tied to the original Title, but leave the new one in place.
7. Now that a new Group Provider has been created for the new title, and the old one is removed, you have successfully updated the Site Title.