We now have available tutorial videos you can follow as well as as the step-by-step guides.
You can not delete an incident once you have created one, but you can change the status of it to Invalid.
Click on the 
icon.
A new pop up will appear, click on Further Information.
Click the Status drop down box, click Invalid and click Save.
If you are unable to follow these instructions, you may not have the required user permissions. Please contact your Site Administrator.