Old Time Machine backups in the trash - how to delete?

Somehow I inadvertently ended up with 15 old Time Machine back up dates in the trash of my Macbook Pro. Even when I click on "delete all items" (including locked items), they do not disappear. I also tried dragging these 15 folders from the trash to the desktop so that I could unlock each one (thinking I could, once they were unlocked, send them back to the trash for deletion). However, when I dragged them to the desktop, they remained in the trash and made a copy of themselves on the desktop. These files are taking up hard drive space that is becoming scarce - what can I do to 1) delete these files from the trash of my Macbook Pro, 2) delete them from the desktop where they now are duplicated in a folder called Old Backups, and 3) how can I delete them from Time Machine since they are truly old and I do not need them (I am not short of space on my Time Machine drive, but it just seems silly to keep something that old when I don't really need it). Please help - this is making me nuts!