How to force delete files in use on Mac?

For some reason that I forget, I have some files in the trash that I cannot delete. The dialog box that comes up says they are in use. I've restarted my machine and they still won't let go.

How can I delete them? I tried dragging to my desktop to delete them in the terminal but they won't drag.

Any insight appreciated. Cheers

[Re-Titled by Moderator]