Type exactly as entered, double-check it, and triple-check it before pressing enter. A typo here could be disastrous:
sudo rm -rf ~/.Trash
Alternatively, you could type this (
without pressing enter afterwards):
sudo rm -rf
...add a space to the end of that, and then drag the offending file into the Terminal window. It'll auto-complete the path for that specific file. Then, press enter and it'll force it to be deleted.
If you don't want to play with the Terminal, I do believe there are several utilities on
MacUpdate that will force delete the trash for you.