Surfactant adsorption on hydrophobic surfaces is of current interest in attempts to solubilize single-wall carbon nanotubes and to render quantum dots biocompatible. A coarse grained method is presented for incorporating a hydrophobic surface into existing liquid force fields by appealing to statistical mechanics and probability theory. The dimensionality problem which arises is overcome with an approximate treatment and the entire procedure is applied to aqueous n-alkyl poly(ethylene oxide) adsorbing onto a graphite surface. The simulations are in excellent agreement with atomic force microscopy data. The mechanism of micelle adsorption onto a partially coated surface is reported for the first time and has implications for the construction of nanotemplates.