The First Order rose from the ashes of the Galactic Empire, and continued the tradition of using Stormtroopers as their main military ground forces. There are five known types of First Order Troopers in the movies. Some can use new stats, others can be modified for.
To create First Order Stormtroopers, Take the regular Imperial Stormtrooper stat block and add Vigilance as a group skill.
First Order Snowtroopers can have the same stats as Stormtrooper Specialty Corps: Snowtroopers, but also take Vigilance as a group skill
For First Order Stormtrooper Sergeants, take the Imperial Stormtrooper Sergeant, downgrade their weapons to a Blaster Rifle with Improved Stock-(Ranged- [Heavy]; Damage 9, Critical 3, Range [Long], Accurate 1, Stun Setting) and add Vigilance 2 to their skills.
Megablaster Heavy Assault Troopers are simply regular Imperial Stormtroopers with the same Vigilance group skill and Light Repeating Blasters with the Bipod Attachment. They can be put into the same minion group as First Order Stormtroopers.
First Order Flametroopers have a new stat block-
First Order Riot Control Troopers – I’m leaving these guys out because their main weapon, the Z-6 Riot Control Baton, is currently in an upcoming book by FFG, Disciples of Harmony, the sourcebook for Consulars. Sorry!