How to delete a Time Machine backup folder from the Bin?

Hello everyone... well I have a MacBook Air, and yesterday I was trying to delete a Time Machine backup folder from a Toshiba external hard drive, and there are some problems with it: every time I want to empty the bin it's an eternal process, last night I was waiting around 4 or 5 hours for empty the bin, but I had to force the computer to shut down (it was too late), now I want to do it for some items that I sent there today but is like the backup folder never disappeared, and there are still appearing items from it wen I open the bin (like outside the folder that sadly still there), it's something really bizarre for me, since I hate computers lol, but I infer that the folder was kinda heavy because now the external hard drive has like 80 GB free. If anyone knows some procedure or solution, all answers about the subject are welcome, thanks for read and for your time.