i have two questions for modding halo pc.

[Warrior_3000]

1.when i have a mod apply. lets say its on blood gluch, and i wanted a different mod to apply,how do i do this. cause every time i PPF it and i try to play the map its just the old mod i have on.

2.i see that some peoples mods are .maps and not .ppf's,how do i play .map mods?