1) The traditional way is by making three tournament norms against master-class opposition.
2) The title can be awarded directly (without need of qualifying via norms) if the player has achieved a certain minimum rating (2200 for IM) AND has won a Zonal / Sub-Zonal which is a qualifier for the World Cup or World Championship competition.
3) As #2, but is a Youth / School event on the Zonal / Sub-Zonal scale.
4) As #2, but if subgroups have been combined then a player can qualify for a direct title if they achieved at least a 50% score, played at least 9 games, and the tournament included at least eight players from five federations.
5) Titles can also be awarded at FIDE's discretion for significant lifetime achievement.
Not sure that's ALL the valid ways, though.
If you are not sure what I mean watch this short dialogue by IM John Bartholomew : First 50 seconds of the video thx.
https://youtu.be/y_a4L8x4qbU
Can you name all possible, valid ways of getting the title, besides usual one? thx.