Since most of this oxygen is locked away in lunar rock, NASA is planning on using moon rovers to not only drill into the moon rock, but to produce oxygen from its surface as well.
(NASA) NASA’s lunar exploration plan currently projects that on-site lunar resources could generate one to two metric tons of oxygen annually. This is roughly the amount of oxygen that four to six people living at a lunar outpost might breathe in a year. The field demonstrations in Hawaii showed how lunar materials might be extracted. It also showcased the hydrogen reduction system used to manufacture oxygen from those materials and how the oxygen would be stored. These experiments help engineers and scientists spot complications that might not be obvious in laboratories.
A prototype system combines a polar prospecting rover and a drill specifically designed to penetrate the harsh lunar soil. The rover’s system demonstrates small-scale oxygen production from regolith. A similar rover could search for water ice and volatile gases such as hydrogen, helium, and nitrogen, in the permanently shadowed craters of the moon’s poles. Carnegie Mellon University of Pittsburgh built the rover, which carries equipment known as the Regolith and Environment Science and Oxygen and Lunar Volatile Extraction.
While developing rovers to convert oxygen from moon rock (even in small amounts) is great, NASA may want to rethink the whole drilling approach, as it may be cheaper to use a lunar vacuum (as replacing bits may become expensive after awhile).