How do I change or edit a map in halo 1 and add stuff?

[Irving]

I want to make a match in battle creek with health packs and shotguns instead of assault rifles and pistols with lots of grenades but I don't know how. please help me

 

[John]

you will need programs like Sapien, Guerilla, Spark Edit. I dont know how to use them but you can find tutorials on youtube