In the final stage of the hydroxylation of methane to methanol by the methane monooxygenase (MMO) enzyme, a binuclear iron−methanol complex (II), expels the methanol and restores the resting state (RS) FeIII−FeIII form of the hydroxylate (MMOH) component to complete the catalytic cycle. The overall process, II → RS, can include protonation, addition of water, expulsion of methanol, and ligand rearrangement, all in an unknown order of occurrence. A model previously applied successfully to describe the hydroxylation mechanism that produces II is used here with the density functional theory to examine a series of intermediate structures and reaction steps to find the lowest-energy reaction path for II → RS. Two different groups of structures and reaction steps are considered; those involving proton transfer from the protein/environment to the complexes (group A) and those that are charge neutral with consideration of internal hydrogen atom migration among the oxygen ligands of the diferric complexes (group B...