You can delete a block in your session by clicking on the dotted menu in the upper left corner of the block and selecting the Delete option.
In case you are not sure if you want to use a specific block in your session, you can also drag it aside to the Notes tab which functions as a 'parking lot' area. If you move a block there, it will stop counting towards the overall timing of your session, but you will be able to move it back to the agenda if you want it later.
You can similarly delete a group of blocks from the upper left corner of the group. Please mind that if you delete a group, then all the blocks within the group will also be deleted.
If you want to delete one of the rooms in your breakout session, you first need to click on that room, and then the small arrow to the right of the room name. Select the 'Delete room' option from the dropdown menu.
If you'd like to delete the entire breakout session, please be sure to click on the dotted menu on the top left of the breakout session, rather than the individual block's menu:
Restoring deleted content
If you’ve deleted a part of your session and you would like to restore the deleted content, then blocks, groups, notes and parallel rooms can all be recovered via the Activity Log up to three days since they were first deleted.