Q: Trash can will not empty

If a Restart doesn't allow you to Empty the Trash...

Goto Finder > Help > type in Trash...

From Finder Help Trash...

" Empty the Trash

Command (⌘)-Shift-Delete

Empty the Trash without any warning or when it contains locked files

Command (⌘)-Shift-Option-Delete

Hold down the Option key, and then choose Finder > Empty Trash "

See here

http://support.apple.com/kb/HT1526

http://www.thexlab.com/faqs/trash.html

Relaunch the Finder, then from the Finder menu bar, select

Finder ▹ Preferences ▹ Advanced

and uncheck the box marked Empty Trash securely. Try again to empty the Trash.