swapping to make a wraith
 

you know that tutorial you showed me, well it worked but im supposed to go to hmt to put it in. how do you swap it with a warthog. make sure you tell me how to do it starting from opening up hmt to playing bloodgulch and going in the wraith. plz!

You mean this tutorial:
http://forums.halomods.com/viewtopic.php?t=5796
It was fairly self explanitary apart from replace the word pelican with the word wraith. You can open b40.map to get a wraith. Scroll down to [mod2] and that is the model you want is vehicles\wraith\wraith. It will then say there are two models. You want model "__unnamed (1)". That's the first two steps explained. Just continue with step 3, and so on.

Afterwards, all you should have to do is swap the metas in the new bloodgulch for the warthog and you should have a wraith.

I hope this answers your question, if not couldyou clarify a little please?

but how do you drive the wraith? whenever i go on bloodgulch its just there as scenery. plz help!

All you need to do is open the map in HMT and select the wraith tag in [vehi]. Scroll down to seat and use the dropdown to select seat 0. The seat name should now be "Wraith Driver" (no "s). Change it to "W-Driver" (again no "s) and you should be done.

now what should the seatname for the covenant dropship be? what should the main id be aswell?

"W-Driver" again I think (re-name seat 0 as this) if you want to drive it.

how do i get in?

I haven't tried it, but it should be walking up to it a pressing "e". I'll give it a go later if that's not the case.