Post-game edits can be accessed by clicking Load past Game button (available for licences with enabled post game edits). Only finalized games can be opened for post-game edits.
In Enter Match Key field (1), insert valid match key and click Next (2).
You will be presented with Action Log Editing view. Select an action to Edit (1) or Delete (2).
You can also select an action (1) and insert a new action earlier or later (2).
Use filters to filter actions by type.
Click Publish and close button to finish the post-game editing.