Once the spacecraft is in its science orbit at the Moon, the lander mission can begin. While the orbiter doesn't care much about what phase the Moon is in, the lander and rover need sunlight for warmth and power, so the timing of launch will be dictated by the necessity to get the lander on the ground at its landing site very soon after local dawn. However, the concept of dawn is a bit tricky, because the landing site is planned to be near the south pole. I haven't seen any recent information on the specific landing site choice. As of 2012, an earlier concept that involved Russian collaboration had proposed landing sites that were quite near the South Pole indeed, at 87.2 and 88.5 degrees south.

The landing will happen entirely autonomously. The lander will separate from the orbiter and immediately perform a deboost maneuver, changing its orbit around the Moon to one with an 18-kilometer periapsis. When it reaches periapsis, the lander will begin the "rough braking phase," braking to reduce its orbit altitude to 7 kilometers.

At an altitude of 7 kilometers, the lander will use a camera to take photos of the lunar surface and determine its relative position and velocity compared to its onboard map of the landing region. The lander will autonomously determine the trajectory necessary to bring it to its desired landing site, and steer itself to a location 100 meters above the site, where it will come to a hover. It will use a hazard avoidance sensor to map the surface for potential hazards and select a safe location for touchdown. The lander will slowly descend until it reaches 2 meters above that location. Then it will cut its engines. The lander will fall to the surface, its four lander legs absorbing the shock of landing. The rover will roll out of the lander shortly after the landing in order to make the most of its brief, two-week primary mission.