Ok, first you will need HMT 3.5 (HaloModdingTools version 3.5)
we will open it, and we will be using map a30 (found in the maps folder, it is a campaign map SP) the real map name is Halo, then 2nd level.
(the halo maps folder is found in C://Program Files/Microsoft Games/Halo/MAPS/ and they're there)
now we have the map open we will go down and select [bipd]Biped just select the little box with the cross inside and it will drop down another selection, from that select "characters\cyborg\cyborg" (this is the current player, it is the Master chief himself, for some reason hes called cyborg)
now near the top, there is a box, at the top of this box says "tag information"
and in this box click swap, now we're about to swap the cyborg (master chief) for the Elite (that tall covanant guy)
you can swap the master chief (cyborg) for any character, so long as it is in the map, if its not in the map, then you cant swap it. so "characters\grunt\grunt" would obviously be the grunt, and "characters\marine_armored\marine armored" would be the marine guy that hang around with you through half the map.
ok, back the the tutorial, once you have clicked swap, go down the little box and select "characters\elite\elite" and then click on it
ok, nearly done, just click save, then click close map file to close the map, if you dont close the map properly you could screw up halo, and your done, just put halo pc on from the desktop.
to tell you the truth i think the controls for the Elite from the campaign maps are a bit "naf" you can also swap the teams around by selecting they're team on that little tick box when the character is selected, and its not just the master chief you can swap around, try swapping the captain on the first map for a grunt
hope this helped
