Can't delete File in Trash, even after reinstall OS

So I have a document in my Trash and I can't delete it because it is "in use". So I decided to reinstall the OS. I upgraded from El Capitan to Sierra. (Not upgraded, I cleaned my SSD with disk- utility and aftere that I installed MacOS Sierra) But the File is even after the complete reinstall still in the trash folder.

I tried to format my SSD mit Gparted, but the Macbook won't start gparted correctly.

Do you know a tool to fully clean my SSD in the Macbook from an external boot program?

Thank you!

Eric

It's an Macbook Pro 13"

Sorry for grammar, I'm from Germany 🙂