How to: Add the BMP3 from the GRM to the Russians

Steps
1. Go to set/multiplayer/units/vehicle_grm.set
2. Copy the line {"bmp3" ("v" cd(390) ci(210) t(all heavy armor armored_warfare combined_arms conquest) s(grm) n1(4) g(cv1) sc(0.05) b(v3) cw(0) cp(11)) {level 1} {research_stage 6} {cost 770} {squad_cost_factor 1}}
3. Paste the line into set/multiplayer/units/vehicle_rus.set
4. Change s(grm) to s(rus)

Background knowledge:
Within the vehicle_rus.set file:
1. S() tells the game what side the vehicle belongs to.
2. The b() is used to denote which button a unit will appear under:
b(s1) = Unit is called in under the first button (where most of your frontline infantry appear)
b(s2) = Unit is called in under the second button (where most of your support infantry appear)
b(v1) = Unit is called in under the third button (where most of your support vehicle/light vehicles appear)
b(v2) = Unit is called in under the fourth button (where most of your medium vehicles appear)
b(v3) = Unit is called in under the first button (where most of your heavy vehicles appear)
b(hero) = Unknown