external drive -- can't remove trash..

I have a very conventional WD external hard drive... I have removed all my files & dir b/c am handing it over to another person.. but discovered all files and dirs I removed are still there, in dir .Trashes... inside this .Trashes dir is a dir '501', all removed dirs and files are there.. but I can't remove them!!

inside dir .Trashes, I tried:

rm -r 501

and get this prompt:

override rwxrwxrwx <myUserName>/staff uchg for 501/books/review.html?


it's doing this for every single file in there.. why is it doing this? don't even know where dir "staff" is (there's no such dir, either in my computer or in the HD)... and whether I do 'y' or 'n' (or do nothing and just press return) it does not remove the files...

pls help.. this is ridiculous.. why is it so hard to remove files from an external drive?

thank you.....

Same as Windows. It is necessary to empty the Trash whilst the external drive is connected and mounted. Suggest with the WD external connected and mounted, go into Disk Utility, select the external and format. This will wipe the drive clean.

If going to a Mac user, format Mac OS Extended (Journaled) and to Windows user format MS-DOS.

actually empying trash in computer did absolutely nothing... finally succeeded with this command:

sudo rm -rf -r 501

('501' being the dir inside .Trashes I wanted removed...)

thank you....