Kitted Out Trophy

By "Kit", the game means the actual class you play as, of which there are 5 that shipped with the game: Gunner, Demolisher, Technician, Doc and Recon but the Recon Kit doesn't unlock until after you have finished the main storyline once. Note: There are plans to add more Kits in the future (with the Phalanx being the first) but it's currently unknown if they will be patched in for free or if players will have to pay for them. At the very least, the Phalanx is free but future Kits might not be.

To level up a Kit, you just have to use it a lot and earn enough kills to reach the 200,000 XP required to max it out but do note that the amount of XP is dependant on your choice of difficulty setting and if you have a Challenge card active which increases the amount earned. Please see this farming video by Legacy Gaming if you want speed things up:

Here are the required XP amounts required for each rank:

1: 10,000
2: 35,000
3: 65,000
4: 95,000
5: 125,000
6: 160,000
7: 200,000
8: 200,000