Removing footage.

I'm trying to find a way to cut out and delete unused footage in my projects.  I video an event from a static position leaving the camera recording for the whole event. It's not always possible to just start or finish the recording at the very begging or end of the event, hence the camera is kept rolling. As a consequence, I have some footage that I want to permanently remove at the begging and end of the media and save disk space. I, ve seen lots of posts regarding removing unused media, etc which has been imported and not used in a project also I saw posts about deleting sub-clips and sequences but that has no effect on the main media footage which remains intact. Where as I wish to cut my media/footage down and delete.

Can anyone offer any suggestions?