Join a chess federation that is a FIDE member
Obtain a FIDE ID through your national federation
Play in FIDE-rated tournaments
Ensure the tournament is registered with FIDE
Play against rated opponents
Score enough games in FIDE-rated events
Meet the minimum performance requirements set by FIDE
Have your results submitted by the tournament organizer or federation
Wait for your rating to appear in the FIDE rating list
Keep playing FIDE-rated events to establish and improve your rating