Deleting specific files within a windows backup?

Hello. I have been using the windows 7 backup tool on windows 10 for a while now, but my 1tb backup drive is now full, despite the fact that the drive it is backing up is less than 1tb. I am not backing up a system image. I know that the problem is that I do a lot of reorganizing and deleting on my main drive. When I go into restore, I can see files and folders in my backup that I deleted long ago. I cannot figure out how to delete them. Is there a way to delete specific files and folders within a windows backup? Thanks.