Removing ZERO boards from IDE

A few months ago I used the board manager to install the ZERO boards in the IDE. I don't need them any more but I cannot figure out how to get rid of them. I have just done a fresh ZIP install of the new Arduino release 1.6.10 and somehow the zero boards are still in the IDE menu. There is no mention of them in boards.txt. How do I obliterate them from the IDE menu and anywhere else they are lurking? Thanks

Pete

Tools -> Board -> Board Manager.

Select "More info" on the board you want to remove. On the right should appear a "Remove" button.

Thankyou SurferTim!

Pete