There are some glitches that you can exploit in Halo 3, like super destructive weapons in forge and no text in halo main menu. However, for more common mods like actually driving the scarab or piloting the pelican/phantom, you have to have a dev mod. You can get that developers kit from Microsoft or Bungie.
You can't
Sorry, I think you can't do this unless you mod halo 3.
There is no Halo 3 mod for Halo Trial. Halo Trial is one of the hardest versions of Halo to mod. There are however, custom maps for Halo Custom Edition. To get Halo Custom Edition, you need to have Halo: Combat Evolved installed on your PC, you also need your CD key. You can download Halo: Custom Edition free.
You cant.
You can't install Halo 3 mods anymore to your xbox.
You cannot. This is impossible.
its easy download it at filefront.com copy this where halo trial halo 1 halo 2 halo 3 mod mods ok?
Yes, you can mod campaign mod on the Halo trial.
No there is not a mod
there are no cheats for xbox but you could download a mod for halo 3 to get all armour
No,, unless you mod the game on the PC
You can't unless you Mod