If you have a recording that you want to delete, open your tour in 360 View. Click the up arrow next to the Record button in the bottom left corner, and click Delete recording. This will immediately delete your recording from your tour. 

To update your published tour, double click on the donut shaped image you wish your tour to start on. This will open 360 View. Position your screen in your desired starting position and then click the blue Publish button in the bottom right hand corner of your screen. This will republish your tour and update it with your changes.