Click on the review button in the match block and scroll to the bottom of the page where you will see an edit result button. The button will indicate what level of admin rights you have and will take you to the results entry page for that result where you can edit it.
Within the edit match page you will be able to edit the match details based on your admin level. If you are unable to edit the details you need then you may not have the right admin level. In this case please get in touch with us and either we can make the changes for you or we'll bump up your admin level so you can make the changes yourself.