This paper addresses the problem of navigating an autonomous moving entity in an environment with both stationary and movable obstacles. If a movable obstacle blocks the path of the entity attempting to reach its goal configuration, the entity is allowed to alter the placement of the obstacle by manipulation (e.g. pushing or pulling), to clear its path. This paper presents a probabilistically complete framework for solving path planning problems among movable obstacles. Heuristics are presented to provide efficient solutions for problems in environments encountered in practical situations.