The easiest way to to get to your destination is a direct flight. Direct flights for from Cozumel to Cancun are offered by:
Aviasales.ge suggests buying tickets for Cozumel – Cancun in advance in order to choose the conditions for your flight that best suit your preferences and budget.
Cozumel airports serving flights to Cancun:
Cancun airports accepting flights from Cozumel: