Open Terminal. Type yes > /tmp/whatever which will create a temp file that fills the disk and encourages the system to delete its other temporary files. Watch free disk space tick down and hopefully magically back up. Press Ctrl+C in terminal to stop it.
Then rm /tmp/whatever to remove the giant file. With luck you'll have more free space than you started with.
Open Terminal. Type
yes > /tmp/whatever
which will create a temp file that fills the disk and encourages the system to delete its other temporary files. Watch free disk space tick down and hopefully magically back up. Press Ctrl+C in terminal to stop it.Then
rm /tmp/whatever
to remove the giant file. With luck you'll have more free space than you started with.