  We consider the simple random walk on the (unique) infinite cluster of
super-critical bond percolation in $\Z^d$ with $d\ge2$. We prove that, for
almost every percolation configuration, the path distribution of the walk
converges weakly to that of non-degenerate, isotropic Brownian motion. Our
analysis is based on the consideration of a harmonic deformation of the
infinite cluster on which the random walk becomes a square-integrable
martingale. The size of the deformation, expressed by the so called corrector,
is estimated by means of ergodicity arguments.
