The 4 categories include Abilities, Co-op, Assault, and Weapons. After one playthrough of the story you will probably be around rank 4-5 in each category on average, so some extra work will have to be done to reach level 10.
The easiest way to max out both the Weapons and Co-op ranks together is to play level 2 section 11 (Gauntlet) until you see a turret right next to the switch you have to push to progress. Don't turn on the switch. Instead get on the turret and there will be an infinite amount of enemies spawning for you kill which will gain you the "Critical Intercept & Intercept" bonuses for Co-op as well as all the bonuses that come within the Weapon category such as headshots, long range kills & suppression kills.
To max out both the Abilities and Assault categories in one go, load up level 2 section 3 (Besieged) and play until the end when you have to fight a few waves of aliens while the elevator arrives. If you don't get into the elevator the enemies will keep spawning here. You should go for Melee kills for the bonus within the Assault category and Shockwave kills for the Abilities category.