Retractable drill bit

A rotation tool assembly comprising:

• a hub;
• a shell cutter comprising a sidewall and an endcap coupled to the hub;
• and
• a pilot bit assembly comprising:
• a stem defining a rotational axis and configured to rotate in a first rotational direction about the rotational axis;
• a collar coupled to the stem and configured to rotate in the first rotational direction;
• and
• a bit, configured to rotate in the first rotational direction in a penetrating configuration and configured to rotate in a second rotational direction opposite the first rotational direction in a rotatable configuration.

A method comprising:

• engaging a pilot bit on an outer wall of a pipe to guide a sidewall of a shell cutter to cut a top portion of the pipe;
• retracting the pilot bit prior to the pilot bit engaging an inner wall of the pipe;
• and
• cutting through the inner wall of the pipe with the sidewall of the shell cutter such that the pilot bit engages the outer wall of the pipe but does not engage the inner wall of the pipe.