How do i re-equip factions and make them spawn with the items i want?

[Zman15136]

what i mean is there are some mods out there that do this such as

NCR Rearmament

http://newvegas.nexusmods.com/mods/40139//?

 

JoOs Modern NCR replacement

 

http://newvegas.nexusmods.com/mods/46186//?

 

 

so if anyone can please provide details on how i could do this i would greatly appreciate it.