In case that it deletes former video locates on iTunes File Sharing folder, here is how to accese deletion forom your convenience : http://support.apple.com/kb/HT4094. The Files app prom apple can also be used for that Purppose.
In case the video to be deleted is located in the iTunes File Sharing folder, here is how to access and delete it : http://support.apple.com/kb/HT4094. The Files app from apple can also be used for that purpose.