Well considering this is discussed 3 or 4 threads down, in a folder marked Mod pack 1, i probably should just point you to that, but as my description was for xb hhd modding, i will post again... even though it is not much different but please remember to check other forums before posting questions that have already been answered (and be clearer in what you want)
1. Make sure you have XXI Explorer. I think the latest version is 1.5.
2. Install/Extract XXI Explorer to a folder
3. Copy character_table.xml from the Modpack to the XXI folder
4. open your WM21 dir in your extracted files.
5. In the main folder, there are some wad files, dvd.wad, dvd2.wad, dvd3.wad and hd.wad. Copy hd.wad to the folder you extracted XXI Explorer to on your XXI folder
6. Run XXI Explorer and seclet open > wad file > then pick hd.wad
7. You should see a list of files in the main window, starting with ai.lua
8. Scroll down to find the file name character_table.xml (you can just click in the main window and type "c" "h" to find it quickly)
9. While character_table is selected, click "Import" It should pop up "This file is larger... Will need to reindex..." or something similar. After "File Imported Successfully" pops up, close XXI explorer
10. Go back your wm21 dir. rename hd.was in the wm21 dir to hd.wad_orig (or whatever, it's just for backup) and copy the hd.wad from your xxi folder to the wm21 folder.
11. Copy the rest of the modpack files to the wm21 folder, I think it shouldn't overwrite anything, but if it prompts, just say no, rename the original, and copy again
12. Then burn