A NOTE FROM LUNTIX
This tutorial is very well written. It needs no images. I was able to follow it without needing images.
Here is the Tutorial
-It's easy to follow-
Be sure to back up your maps before modding... here's how:
If you just selected "express install" or didn't mess with the install directory:
Go to My Computer, then "C:Program Files\Microsoft Games\Halo\MAPS"
Press "ctrl" + "a".
Go back up to the Halo folder, and create a new folder. Title the folder "BACKUPS".
Go into this folder, and hit "ctrl" + "v".
Wait a few moments for the copy operation to complete. On Windows XP platforms, this should only take about one minute max, depending slightly on your HD rotating speed and sometimes processor speed (which would only influence the write speed if it were a slow processor, like say, 700 and below).
Else If ("you selected your own directory" = 1)
Follow the tut as above, except use the directory you used to install Halo in.
To install a mod, you must affect a map in your "MAPS" folder. This is done in a different number of ways, depending on what file types you receive:
If it's a .map file
Right-click the mod you want installed and hit copy.
Go to "C:\Program Files\Microsoft Games\Halo\MAPS" again, and select paste. If it doesn't overwrite another file, you have a problem and have rights to ask about your problem in the thread you found the mod...
If it's a .ppf file
You will need PPF-O-Matic for this.
Open up ppf-o-matic ( Download PPF-O-Matic here).
Where it says "ISO file", click the little disk next to it.
click on the "ISO" box, and select "all files" instead.
browse to your "MAPS" folder.
select the appropriate map to apply the ppf to (the filename should tell you this), and click "open".
Hit "apply". If it says "file sizes are not the same!", or something like that, you have either applied the ppf to the wrong file, or the ppf is **** (a rare occurrence, don't immediately go for this explanation).
If you receive a ".rar" file:
A rar is a compressed file, much like a ".zip" file. it can be extracted by WinRAR, found at rarlab.com (note: be sure to get WinRAR, and not anything relating to ".tar", which is a very old file type designed only to bunch files together in one file uncompressed.
Double click on the file; it should open in WinRAR. Simply find the "extract all" (or whatever it's called) button, and why not check the "open in explorer" button in the bottom left corner to save us the trouble of finding the decompressed folder by ourselves?
There should be files in your new folder, either (magically!) .ppf's or .map's! miracle, no? Follow the above steps to apply them.
A random piece of advice that I've never seen to be useful, but why not...
If you receive any .exe, .bat, .vb/s files or anything else besides ppf's, map's, text documents, or image (.jpg, .bmp, .gif, .png etc.) files, they could be infected with viruses or other malicious files, and should not be trusted.
Keep in mind that often times you will be required to install multiple .ppf files or a .map file and a .ppf file.
You need HMT for this. Get it at HMTv3.5.
Unzip the file your skins came in using WinRAR and place the skins in a folder.
Start up HMT.
In HMT, open up the map Bloodgulch. It's in mycomputer/C: localdisk/programfiles/microsoftgames/halo/maps.
Once you've opened Bloodgulch, go to "bitmaps". It's near the top of the list of stuff that showed up when you opened Bloodgulch. Duh.
Find which thing the skins are for and install them. i.e. If it's for the chaingun on a warthog, go the "Vehicles/warthog/bitmaps/warthog chaingun.
Click "inject texture".
Browse for the skin you want to install and hit ok.
For this tutorial, I'm going to assume you've downloaded HaloCE. If not, go to the gearbox forums. Try all the links till you find one that works.
Create a folder for your HaloCE stuff, otherwise it gets crowded. I would suggest putting a shortcut to the HaloCE maps folder for easy access.
Download a map. The best place is Halo Mods.
Save the map to the folder you created for HaloCE.
Open it up using WinRAR.
Take the .map file out of WinRAR and place it in the HaloCE folder you made.
Copy and paste into the map folder for HaloCE.