The answer to the Question “How to solve the world largest puzzle” is given on Jibbl.org.
The world’s largest Sudoku puzzle was constructed on a hillside near Chipping Sodbury in the UK, very close to the Bath exit of the M4 motorway. The Sudoku is visible to motorists traveling Eastbound towards London.
The size of the puzzle measures almost 85 meter square. The solutions to this Sudoku and a larger picture of the Sudoku can be found at Jibbl.org.